A solar cell, a cell assembly, and a photovoltaic system

Abstract

This invention provides a solar cell, a battery module, and a photovoltaic system. The solar cell includes a substrate with a first edge and a second edge. A first edge busbar, a second edge busbar, and a plurality of first and second collection grids arranged alternately along a first direction are disposed on the substrate. The first edge busbar includes a plurality of first sub-lines arranged sequentially along the first direction, with adjacent first sub-lines disconnected from each other. The second edge busbar includes a plurality of second sub-lines arranged sequentially along the first direction, with adjacent second sub-lines disconnected from each other. This design allows through-holes to be provided only at positions corresponding to the first and second sub-lines on the solar cell screen, while no through-holes are provided at positions corresponding to the areas between adjacent first and second sub-lines. This enhances the structural strength of the solar cell screen, improves its lifespan and printing quality, and increases the yield of the solar cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more particularly to a solar cell, a battery module, and a photovoltaic system. Background Technology

[0002] Solar cells, as efficient and clean energy conversion devices, are widely used in various photovoltaic power generation systems. A solar cell consists of a silicon substrate and electrodes disposed on the silicon substrate. The electrodes are responsible for effectively collecting electron-hole pairs (charge carriers) generated by the silicon material under sunlight and guiding the directional migration of these charge carriers to convert them into usable electrical energy. However, the yield of existing solar cells is relatively low. Summary of the Invention

[0003] This invention provides a solar cell, a battery module, and a photovoltaic system to improve the yield of solar cells.

[0004] According to one aspect of the present invention, a solar cell is provided, the solar cell comprising: The substrate includes a first edge and a second edge, the first edge and the second edge extending along a first direction and disposed opposite to each other along a second direction, the first direction and the second direction intersecting each other; The substrate is provided with a first edge busbar, a second edge busbar, and a plurality of first and second collection grids arranged alternately along the first direction. The first and second collection grids extend along the second direction. The first collection grid is electrically connected to the first edge busbar, and the second collection grid is electrically connected to the second edge busbar. The first edge busbar is adjacent to the first edge and extends along the first direction. The second edge busbar is adjacent to the second edge and extends along the first direction. The first edge busbar includes a plurality of first sub-lines arranged sequentially along a first direction, with adjacent first sub-lines disconnected from each other; and / or, the second edge busbar includes a plurality of second sub-lines arranged sequentially along a first direction, with adjacent second sub-lines disconnected from each other.

[0005] Optionally, the distance between adjacent first sub-lines along the first direction is less than the distance between two adjacent first collection grid lines along the first direction; And / or, the distance between adjacent second sub-lines along the first direction is less than the distance between two adjacent second collection grid lines along the first direction.

[0006] Optionally, the ratio of the length of the first sub-line to the spacing between adjacent first sub-lines is greater than or equal to 1.5 and less than 100. The ratio of the length of the second sub-line to the spacing between adjacent second sub-lines is greater than or equal to 1.5 and less than 100.

[0007] Optionally, the ratio of the spacing between adjacent first sub-lines to the spacing between adjacent first collection grid lines along the first direction is greater than or equal to 0.025 and less than or equal to 0.75. The ratio of the spacing between adjacent second sub-lines to the spacing between adjacent second collection grid lines along the first direction is greater than or equal to 0.025 and less than or equal to 0.75.

[0008] Optionally, the distance between adjacent first sub-lines along the first direction is greater than or equal to 0.05 mm and less than or equal to 1.5 mm; The distance between adjacent second sub-lines along the first direction is greater than or equal to 0.05 mm and less than or equal to 1.5 mm; Optionally, the distance between two adjacent first collection grid lines along the first direction is greater than or equal to 0.5 mm and less than or equal to 2 mm; The distance between two adjacent second collection grid lines along the first direction is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0009] Optionally, the first surface of the substrate is further provided with a first bus gate line, the first bus gate line extends along a second direction, and the first bus gate line is electrically connected to the first edge bus gate line; the first surface has a first serial connection area and a second serial connection area arranged alternately along the second direction, the first serial connection area includes a first edge serial connection area, the first edge serial connection area is the first serial connection area closest to the first edge, the first edge serial connection area includes a plurality of first external pins, and the first bus gate line is connected to the first external pins; Each of the first busbars is connected to a first sub-line, and each of the first sub-lines is connected to at least one of the first busbars. The first surface of the substrate is further provided with a second bus gate line, which extends along the second direction; the second bus gate line is electrically connected to the second edge bus gate line; the second serial connection area includes a second edge serial connection area, which is the second serial connection area closest to the second edge, and the second edge serial connection area includes a plurality of second external pins; the second bus gate line is connected to the second external pins; Each of the second busbars is connected to a second sub-line, and the second sub-line is connected to at least one of the second busbars.

[0010] Optionally, among the first collection grid lines connected to the same first sub-line, the number of first collection grid lines located on both sides of the first busbar connected to the first sub-line along the first direction are equal or differ by 1. In the second collection grid lines connected to the same second sub-line, along the first direction, the number of second collection grid lines located on both sides of the second busbar connected to the second sub-line are equal or differ by 1.

[0011] Optionally, the distance between the first collection grid line connected to the first sub-line and the end of the first sub-line along the first direction is greater than or equal to 50 micrometers. In the second collection grid line connected to the second sub-line, the distance between the second collection grid line closest to the end of the second sub-line and the end of the second sub-line along the first direction is greater than or equal to 50 micrometers.

[0012] Optionally, the lengths of the first sub-lines along the first direction are the same, and the lengths of the second sub-lines along the first direction are also the same.

[0013] Optionally, the line width of the first sub-line gradually decreases from the central region of the first sub-line towards both ends; The line width of the second sub-line gradually decreases from the central region of the first sub-line toward both ends.

[0014] Optionally, the ratio of the maximum line width to the minimum line width of the first sub-line is greater than or equal to 2 and less than or equal to 10. The ratio of the maximum line width to the minimum line width of the second sub-line is greater than or equal to 2 and less than or equal to 10.

[0015] Optionally, the ratio of the linewidth of the first sub-line to the linewidth of the first collection grid line is greater than or equal to 0.1 and less than or equal to 0.9. The ratio of the linewidth of the second sub-line to the linewidth of the second collection grid line is greater than or equal to 0.1 and less than or equal to 0.9; The ratio of the linewidth of the first sub-line to the linewidth of the first busbar is greater than or equal to 0.1 and less than or equal to 0.9; The ratio of the linewidth of the second sub-line to the linewidth of the second busbar is greater than or equal to 0.1 and less than or equal to 0.9.

[0016] Optionally, the ratio of the linewidth of the first busbar to the linewidth of the first collection bar is greater than or equal to 0.05 and less than or equal to 0.5. The ratio of the linewidth of the second busbar to the linewidth of the second collection busbar is greater than or equal to 0.05 and less than or equal to 0.5.

[0017] According to another aspect of the present invention, a battery assembly is provided, including the solar cell described in any embodiment of the present invention.

[0018] According to another aspect of the present invention, a photovoltaic system is provided, including the battery module described in any embodiment of the present invention.

[0019] The solar cell of this invention includes a substrate, which includes a first edge. A first edge busbar and a plurality of first and second collection grids arranged alternately along a first direction are disposed on the substrate. The first edge busbar includes a plurality of first sub-lines arranged alternately along the first direction. Adjacent first sub-lines are disconnected from each other, i.e., the first edge busbar has a segmented structure. This allows through-holes to be provided only at positions corresponding to the first sub-lines on the solar cell screen, while no through-holes are provided at positions corresponding to areas between adjacent first sub-lines. This enhances the structural strength of the solar cell screen, improves its lifespan and printing quality, and increases the yield of the solar cell.

[0020] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. 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 the structure of a solar cell provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of another solar cell structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the first edge busbar in the related technology; Figure 4 This is a schematic diagram of the structure of a solar cell screen in related technologies; Figure 5 This is a printed effect diagram of the first edge busbar in the related technology; Figure 6 This is a schematic diagram of the structure of a solar cell screen provided in an embodiment of the present invention; Figure 7 This is a printing effect diagram of the first edge busbar line according to an embodiment of the present invention; Figure 8 This is an enlarged structural schematic diagram of a solar cell provided in an embodiment of the present invention; Figure 9 This is an enlarged schematic diagram of another solar cell structure provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0023] Reference numerals: 10-substrate, 11-first edge, 20-first edge busbar, 30-first collection grid, 40-second collection grid, 21-first sub-line, 12-second edge, 50-second edge busbar, 51-second sub-line, 60-via segment, 61-via, 70-first busbar, 80-first serial connection area, 90-second serial connection area, 81-first edge serial connection area, 811-first external pin, 100-second busbar, 91-second edge serial connection area, 911-second external pin. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] This invention provides a solar cell. Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another solar cell structure provided in an embodiment of the present invention, with reference to... Figure 1 and Figure 2 The solar cells include: The base 10 includes a first edge 11 and a second edge 12, the first edge 11 and the second edge 12 extend along a first direction X and are disposed opposite each other along a second direction Y, the first direction X and the second direction Y intersect each other; The substrate 10 is provided with a first edge busbar 20, a second edge busbar 50, and a plurality of first collection grids 30 and second collection grids 40 arranged alternately along a first direction X. The first collection grids 30 and second collection grids 40 extend along a second direction Y. The first collection grids 30 are electrically connected to the first edge busbar 20, and the second collection grids 40 are electrically connected to the second edge busbar 50. The first edge busbar 20 is adjacent to the first edge 11 and extends along the first direction Y. The second edge busbar 50 is adjacent to the second edge 12 and extends along the first direction X. The first edge busbar 20 includes a plurality of first sub-lines 21 arranged sequentially along the first direction X, with adjacent first sub-lines 21 being disconnected from each other; and / or, the second edge busbar 50 includes a plurality of second sub-lines 51 arranged sequentially along the first direction X, with adjacent second sub-lines 51 being disconnected from each other.

[0027] Specifically, the substrate 10 may include a silicon substrate and various functional layers stacked on the silicon substrate. The functional layers include a first doped layer and a second doped layer. The first doped layer can be a P-type doped layer, and the second doped layer can be an N-type doped layer. Furthermore, the functional layers may also include tunneling layers or other films. The silicon substrate can be either an N-type or P-type silicon substrate. The first collection gate line 30 and the second collection gate line 40 have different polarities. The first collection gate line 30 is disposed on and in contact with the first doped layer, and is used to collect charge carriers from the first doped layer. The second collection gate line 40 is disposed on and in contact with the second doped layer, and is used to collect charge carriers from the second doped layer. The first edge bus gate line 20 is used to transport the charge carriers collected by the first collection gate line 30. The first edge bus gate line 20 is printed onto the substrate using a solar cell screen printing plate. Figure 3 This is a schematic diagram of the first edge busbar in the related technology. Figure 4 This is a schematic diagram of the structure of a solar cell screen in related technologies. Figure 5 This is a printed image of the first edge busbar in the related technology. Figure 4 The image on the right is a magnified view of a portion of the image on the left. (Reference) Figures 3-5In related technologies, the first edge busbar 20 is a continuous grid line. On the solar cell screen, through-holes 61 are needed to print the first edge busbar 20. During printing, a squeegee applies a certain force to the solar cell screen, scraping from one end to the other, allowing the paste to pass through the through-holes 61 and be printed onto the solar cell substrate. Because through-holes 61 are provided at the corresponding positions of the first edge busbar 20, the structural strength at this position is lower than at other positions. This makes the solar cell screen prone to damage during printing at the through-holes 61, thus reducing the lifespan of the solar cell screen. Furthermore, as the degree of damage to the solar cell screen increases, the printing quality of the first edge busbar 20 is affected. Figure 5 As shown, overflow at a portion of the first edge busbar 20 causes an increase in width, making it prone to short-circuiting with other busbars and resulting in a decrease in solar cell yield. See details... Figure 3 The solar cell screen is made of metal. A through-hole area of ​​a certain width is set at the position corresponding to the first edge busbar. Due to the current manufacturing precision of through-holes, the through-hole area on the solar cell screen is usually large. It is necessary to fill the through-hole 61 at the edge with an adhesive layer. As the usage time increases, the through-hole area deforms, causing the adhesive layer to be damaged. This causes the through-hole at the adhesive filling position to leak downwards, resulting in the first edge busbar 20 becoming wider and more prone to short circuit with other busbars.

[0028] Figure 6 This is a schematic diagram of the structure of a solar cell screen provided in an embodiment of the present invention. Figure 7 This is a printing effect diagram of the first edge busbar line according to an embodiment of the present invention, for reference. Figure 6 and Figure 7 In this embodiment, the first edge busbar 20 includes a plurality of first sub-lines 21 arranged sequentially along the first direction X. Adjacent first sub-lines 21 are disconnected from each other, that is, the first edge busbar 20 has a segmented structure. Correspondingly, the through holes on the solar cell screen are also segmented, that is, the solar cell screen is provided with multiple through hole segments 60, and there are no through holes between adjacent through hole segments 60, thereby enhancing the structural strength of the solar cell screen, improving the service life and printing quality of the solar cell screen, and improving the yield of solar cells.

[0029] The second edge busbar 50 is used to transmit the charge carriers collected by the second collection busbar 40. The second edge busbar 50 includes a plurality of second sub-lines 51 arranged sequentially along the first direction X. Adjacent second sub-lines 51 are disconnected from each other, that is, the second edge busbar 50 has a segmented structure. Correspondingly, the through holes on the solar cell screen corresponding to the second edge busbar 50 are also segmented structures. That is, the solar cell screen is provided with multiple through hole segments, and there are no through holes between adjacent through hole segments, thereby enhancing the structural strength of the solar cell screen, improving the service life and printing quality of the solar cell screen, and improving the yield of solar cells.

[0030] On the solar cell screen, the area between adjacent second sub-lines 51 is made of nickel alloy. The thickness of this area is equal to that of the surrounding area and there are no through holes. This design prevents the solar cell screen from cracking due to stress concentration, thus improving its lifespan. Through holes are provided in the areas where the second sub-lines 51 are printed on the solar cell screen. An adhesive film is applied to these through holes (excluding the areas where the second sub-lines 51 are printed) to prevent ink from seeping into the areas where the first collecting grid line 30 and the second collecting grid line 40 are printed. This further improves the lifespan and printing quality of the solar cell screen, ultimately increasing the yield and overall quality of the solar cells.

[0031] The solar cell of this invention includes a substrate with a first edge and a second edge. A first edge busbar, a second edge busbar, and a plurality of first and second collection grids arranged alternately along a first direction are disposed on the substrate. The first edge busbar includes a plurality of first sub-lines arranged sequentially along the first direction, with adjacent first sub-lines disconnected from each other. That is, the first edge busbar has a segmented structure, allowing through-holes to be provided only at positions corresponding to the first sub-lines on the solar cell screen, while no through-holes are provided at positions corresponding to the areas between adjacent first sub-lines. The second edge busbar includes a plurality of second sub-lines arranged sequentially along the first direction, with adjacent second sub-lines disconnected from each other. That is, the second edge busbar also has a segmented structure, allowing through-holes to be provided only at positions corresponding to the second sub-lines on the solar cell screen, while no through-holes are provided at positions corresponding to the areas between adjacent second sub-lines. This enhances the structural strength of the solar cell screen, improves its lifespan and printing quality, and increases the yield of the solar cell.

[0032] Figure 8 This is an enlarged structural schematic diagram of a solar cell provided in an embodiment of the present invention. Figure 9 This is an enlarged structural schematic diagram of another solar cell provided in an embodiment of the present invention, with reference to... Figures 7-9Optionally, the distance L1 between adjacent first sub-lines 21 along the first direction X is less than the distance L2 between two adjacent first collection grid lines 30 along the first direction X. And / or, the distance L3 between adjacent second sub-lines 51 along the first direction X is less than the distance L4 between two adjacent second collection grid lines 40 along the first direction X.

[0033] Specifically, the distance L1 between adjacent first sub-lines 21 is less than the distance L2 between two adjacent first collection grid lines 30 along the first direction X, ensuring that at the break between adjacent first sub-lines 21, each first collection grid line 30 can be connected to the corresponding first sub-line 21.

[0034] The distance L4 between adjacent second sub-lines 51 is less than the distance L3 between two adjacent second collection grid lines 40 along the first direction X, ensuring that at the break between adjacent second sub-lines 51, each second collection grid line 40 can be connected to the corresponding second sub-line 51.

[0035] refer to Figure 8 and Figure 9 Optionally, the distance L1 between adjacent first sub-lines along the first direction X is greater than or equal to 0.05 mm and less than or equal to 1.5 mm. The distance L4 between adjacent second sub-lines 51 along the first direction X is greater than or equal to 0.05 mm and less than or equal to 1.5 mm.

[0036] Optionally, the distance L2 between two adjacent first collection grid lines 30 along the first direction X is greater than or equal to 0.5 mm and less than or equal to 2 mm; The distance L3 between two adjacent second collection grid lines 40 along the first direction is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0037] Specifically, if the distance L1 between adjacent first sub-lines 21 along the first direction X is too small, the distance between the through-hole segments of adjacent first sub-lines 21 printed on the solar cell screen will be too small, limiting the improvement in the structural strength and lifespan of the solar cell screen. If the distance L1 between adjacent first sub-lines 21 along the first direction X is too large, it may result in the first collecting grid line 30 failing to connect with the first sub-line 21. By setting the distance L1 between adjacent first sub-lines 21 along the first direction X to be greater than or equal to 0.05 mm and less than or equal to 1.5 mm, the structural strength and lifespan of the solar cell screen can be improved, further increasing the yield of the solar cell. For example, the distance L1 between adjacent first sub-lines along the first direction X can be 0.05 mm, 0.5 mm, or 1.5 mm, etc.

[0038] If the distance L4 between adjacent second sub-lines 51 along the first direction X is too small, the distance between the through-hole segments of adjacent second sub-lines 51 printed on the solar cell screen will be too small, limiting the improvement in the structural strength and lifespan of the solar cell screen. If the distance L4 between adjacent second sub-lines 51 along the first direction X is too large, it may result in the second collecting grid line 40 failing to connect with the second sub-lines 51. By setting the distance L4 between adjacent second sub-lines 51 along the first direction X to be greater than or equal to 0.05 mm and less than or equal to 1.5 mm, the structural strength and lifespan of the solar cell screen can be improved, further increasing the yield of the solar cell. For example, the distance L4 between adjacent second sub-lines 51 along the first direction X can be 0.05 mm, 0.5 mm, or 1.5 mm, etc.

[0039] refer to Figure 8 and Figure 9 Optionally, the ratio of the length of the first sub-line 21 to the spacing L1 between adjacent first sub-lines 21 is greater than or equal to 1.5 and less than 100. The ratio of the length of the second sub-line 51 to the spacing L3 between adjacent second sub-lines 51 is greater than or equal to 1.5 and less than 100. Optionally, the ratio of the spacing L1 between adjacent first sub-lines 21 to the spacing L2 between adjacent first collection grid lines 30 is greater than or equal to 0.025 and less than or equal to 0.75. The ratio L4 of the spacing L3 between adjacent second sub-lines 51 to the spacing L4 between adjacent second collection grid lines 40 is greater than or equal to 0.025 and less than or equal to 0.75.

[0040] For example, the length of the first sub-line is 2.94 mm, and the length of the second sub-line is 2.94 mm.

[0041] This configuration ensures that the first sub-line 21 can better collect the carriers of the first collection grid line 30, the second sub-line 51 can better collect the carriers of the second collection grid line 40, and can also better improve the structural strength of the solar cell grid.

[0042] Based on the above embodiments, refer to Figure 1 and Figure 2Optionally, the first surface of the substrate 10 is further provided with a first bus gate line 70, which extends along the second direction Y; the first bus gate line 70 is electrically connected to the first edge bus gate line 20; the first surface has a first serial connection area 80 and a second serial connection area 90 arranged alternately along the second direction Y, the first serial connection area 80 includes a first edge serial connection area 81, the first edge serial connection area 81 is the first serial connection area 80 closest to the first edge 11, the first edge serial connection area 81 includes a plurality of first external pins 811, and the first bus gate line 70 is connected to the first external pins 811; Each first busbar 70 is connected to a first sub-line 21, and each first sub-line 21 is connected to at least one first busbar 70.

[0043] Specifically, both the first series connection region 80 and the second series connection region 90 extend along the first direction X. The first collecting gate line 30 is disconnected at the second series connection region 90 and connected to an external pin in the first series connection region 80. The external pin in the first series connection region 80 is used to connect to the solder ribbon, transmitting the charge carriers of the first collecting gate line 30 through the solder ribbon. The first edge series connection region 81 is the first series connection region 80 closest to the first edge 11. The first bus gate line 70 is used to collect the charge carriers of the first collecting gate line 30 connected to it and transmit them to the first external pin 811 of the first edge series connection region 81. By setting each first bus gate line 70 to be connected to a first sub-line 21, and each first sub-line 21 to be connected to at least one first bus gate line 70, the charge carriers of the first collecting gate line 30 connected to the first sub-line 21 can be transmitted to the first external pin 811 through the first bus gate line 70, ensuring current transmission efficiency.

[0044] The first surface of the substrate 10 is further provided with a second bus gate 100, which extends along the second direction Y; the second bus gate 100 is electrically connected to the second edge bus gate 50; the second serial region 90 includes a second edge serial region 91, which is located in the second serial region 90 closest to the second edge 12, and includes a plurality of second external pins 911; the second bus gate 100 is connected to the second external pins 911; Each second bus gate 100 is connected to a second sub-line 51, and the second sub-line 51 is connected to at least one second bus gate 100. Specifically, the second collecting gate 40 is disconnected in the first serial connection area 80, and the second collecting gate 40 is connected to an external pin in the second serial connection area 90. The external pin in the second serial connection area 90 is used to connect to the solder ribbon, so that the charge carriers of the second collecting gate 40 are transferred out through the solder ribbon. By setting each second bus gate 100 to a second sub-line 51, and the second sub-line 51 to at least one second bus gate 100, the charge carriers of the second collecting gate 40 connected to the second sub-line 51 can be transferred to the second external pin 911 through the second bus gate 100, ensuring current transfer efficiency.

[0045] Based on the above embodiments, optionally, among the first collection grid lines 30 connected to the same first sub-line 21, the number of first collection grid lines 30 located on both sides of the first busbar 70 connected to the first sub-line 21 along the first direction X is equal or differs by 1.

[0046] Specifically, when the number of first collection grids 30 between two adjacent first busbars 70 is even, the number of first collection grids 30 on both sides of the first busbar 70 connected to the first sub-line 21 is equal. When the number of first collection grids 30 between two adjacent first busbars 70 is odd, the number of first collection grids 30 on both sides of the first busbar 30 connected to the first sub-line 21 differs by 1. This configuration ensures a more balanced current transmission on each first sub-line 21, improving current transmission efficiency.

[0047] Based on the above embodiments, optionally, among the second collection grid lines 40 connected to the same second sub-line 51, the number of second collection grid lines 40 located on both sides of the second busbar 100 connected to the second sub-line 51 along the first direction X are equal or differ by 1.

[0048] Specifically, when the number of second collection grids 40 between two adjacent second busbars 100 is even, the number of second collection grids 40 on both sides of the second busbar 100 connected to the second sub-line 51 is equal. When the number of second collection grids 40 between two adjacent second busbars 100 is odd, the number of second collection grids 40 on both sides of the second busbar 100 connected to the second sub-line 51 differs by 1. This configuration ensures a more balanced current transmission on each second sub-line 51, improving current transmission efficiency.

[0049] Based on the above embodiments, refer to Figure 8 and Figure 9Optionally, the distance L5 between the end of the first collection grid line 30 that is closest to the end of the first collection grid line 21 and the end of the first collection grid line 21 is greater than or equal to 50 micrometers. In the second collection grid line 40 connected to the second sub-line 51, the distance L6 between the second collection grid line 40 closest to the end of the second sub-line 51 and the end of the second sub-line 51 is greater than or equal to 50 micrometers.

[0050] Specifically, the distance L5 between the end of the first collection grid line 30, which is closest to the end of the first collection grid line 21, and the end of the first sub-line 21 is the straight-line distance from the end of the first sub-line 21 to the edge of the first collection grid line 30, which is closest to the end of the first sub-line 21. If the distance L5 between the end of the first collection grid line 30, which is closest to the end of the first sub-line 21, and the end of the first sub-line 21 is too small, process deviations during the printing of the first sub-line 21 may prevent the connection between the first sub-line 21 and the first collection grid line 30, which is closest to the end of the first sub-line 21, thus reducing the yield of the solar cell. By setting the distance L5 between the end of the first collection grid line 30, which is closest to the end of the first sub-line 21, and the end of the first sub-line 21 to be greater than or equal to 50 micrometers, the structural strength and lifespan of the solar cell screen can be enhanced, further improving the yield of the solar cell and reducing the cost. For example, the distance L5 between the end of the first collection grid line 30, which is closest to the end of the first collection grid line 21, and the end of the first collection grid line 21 can be 50 micrometers, 55 micrometers, or 65 micrometers, etc.

[0051] In the second collection grid line 40 connected to the second sub-line 51, the distance L6 between the end of the second collection grid line 40 closest to the end of the second sub-line 51 and the end of the second sub-line 51 is the straight-line distance from the end of the second sub-line 51 to the edge of the second collection grid line 40 closest to the end of the second sub-line 51. If the distance L6 between the end of the second collection grid line 40 connected to the second sub-line 51 is too small, process deviations during the printing of the second sub-line 51 may prevent the connection between the two lines, reducing the yield of the solar cell. By setting the distance L6 between the end of the second collection grid line 40 connected to the second sub-line 51 to be greater than or equal to 50 micrometers, the structural strength and lifespan of the solar cell screen can be enhanced, further improving the yield of the solar cell and reducing costs. For example, in the second collection grid line 40 connected to the second sub-line 51, the distance L6 between the second collection grid line 40 closest to the end of the second sub-line 51 and the end of the second sub-line 51 can be 50 micrometers, 55 micrometers or 65 micrometers, etc.

[0052] Based on the above embodiments, optionally, different first sub-lines 21 have the same length along the first direction X, and different second sub-lines 51 have the same length along the first direction X.

[0053] This configuration ensures that the number of first collection grid lines 30 connected to different first sub-lines 21 is the same, that the current transmitted by each first sub-line 21 is the same or similar, and that each sub-line 21 has high current collection efficiency. Similarly, it ensures that the number of second collection grid lines 40 connected to different second sub-lines 51 is the same, that the current transmitted by each second sub-line 40 is the same or similar, and that each pair of sub-lines 40 has high current collection efficiency.

[0054] Based on the above embodiments, Figure 10 This is a schematic diagram of another type of solar cell provided by the present invention, with reference to... Figure 10 Optionally, the line width of the first sub-line 21 gradually decreases from the central region of the first sub-line 21 towards both ends; The line width of the second sub-line 51 gradually decreases from the central region of the second sub-line 51 towards both ends.

[0055] Specifically, when the first sub-line 21 is connected to a first busbar 70, the central region includes the location where the first sub-line 21 is connected to the first busbar 70. When the second sub-line 51 is connected to a second busbar 100, the central region includes the location where the second sub-line 51 is connected to the second busbar 100.

[0056] Since the current transmitted in the central region of the first sub-line 21 is the largest, by setting the line width of the first sub-line 21 to gradually decrease from the central region towards both ends, the resistance of the first sub-line 21 gradually decreases as the transmitted current increases, thereby reducing transmission loss and improving battery efficiency. Similarly, since the current transmitted in the central region of the second sub-line 51 is the largest, by setting the line width of the second sub-line 51 to gradually decrease from the central region towards both ends, the resistance of the second sub-line gradually decreases as the transmitted current increases, thereby reducing transmission loss and improving battery efficiency.

[0057] Based on the above embodiments, optionally, the ratio of the maximum line width to the minimum line width of the first sub-line 21 is greater than or equal to 2 and less than or equal to 10. The ratio of the maximum line width to the minimum line width of the second sub-line 51 is greater than or equal to 2 and less than or equal to 10; Optionally, the ratio of the linewidth of the first sub-line 21 to the linewidth of the first collection grid line is greater than or equal to 0.1 and less than or equal to 0.9. The ratio of the linewidth of the second sub-line 51 to the linewidth of the second collection grid line is greater than or equal to 0.1 and less than or equal to 0.9. The ratio of the line width of the first sub-line 21 to the line width of the first busbar is greater than or equal to 0.1 and less than or equal to 0.9; The ratio of the linewidth of the second sub-line 51 to the linewidth of the second busbar is greater than or equal to 0.1 and less than or equal to 0.9.

[0058] Optionally, the ratio of the linewidth of the first busbar 70 to the linewidth of the first collection busbar 30 is greater than or equal to 0.05 and less than or equal to 0.5. The ratio of the linewidth of the second busbar 100 to the linewidth of the second collection busbar 40 is greater than or equal to 0.05 and less than or equal to 0.5.

[0059] Using the above-mentioned linewidth can save slurry while ensuring low current collection loss.

[0060] For example, the maximum linewidth of the first sub-line 21 can be 50µm and the minimum linewidth can be 10µm; the maximum linewidth of the second sub-line 511 can be 50µm and the minimum linewidth can be 10µm; the linewidth of the first busbar 70 can be 50-70µm, for example, 60µm; and the linewidth of the second busbar 100 can be 70-90µm, for example, 80µm.

[0061] This invention provides a battery assembly, which includes a solar cell in any embodiment.

[0062] A battery module may include multiple solar cells, which can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current output. For example, the connection between individual cells can be achieved by welding ribbons, or the connection between battery strings can be achieved by busbars.

[0063] The battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the light-facing side of the solar cell and the photovoltaic glass, the back-facing side and the backsheet, and adjacent cells. As a filler, it can be a transparent colloid with good light transmittance and aging resistance; for example, EVA film or POE film can be used, and the choice is based on the specific circumstances and is not limited here. The photovoltaic glass can cover the encapsulating film on the light-facing side of the solar cell. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of ultra-clear glass can reach over 92%, which can protect the solar cell while minimizing the impact on its efficiency. Simultaneously, the encapsulating film can bond the photovoltaic glass and the solar cell together, and its presence provides sealing, insulation, waterproofing, and moisture protection for the solar cell.

[0064] The backsheet can be attached to the encapsulating film on the back side of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0065] The battery module of this invention belongs to the same inventive concept as the solar cell described in the above embodiments of this invention and has corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the solar cell described in any embodiment of this invention.

[0066] This invention provides a photovoltaic system, which includes the battery module described in the above embodiments.

[0067] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0068] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0069] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A solar cell, characterized in that, include: The substrate includes a first edge and a second edge, the first edge and the second edge extending along a first direction and disposed opposite to each other along a second direction, the first direction and the second direction intersecting each other; The substrate is provided with a first edge busbar, a second edge busbar, and a plurality of first and second collection grids arranged alternately along the first direction. The first and second collection grids extend along the second direction. The first collection grid is electrically connected to the first edge busbar, and the second collection grid is electrically connected to the second edge busbar. The first edge busbar is adjacent to the first edge and extends along the first direction. The second edge busbar is adjacent to the second edge and extends along the first direction. The first edge busbar includes a plurality of first sub-lines arranged sequentially along a first direction, with adjacent first sub-lines disconnected from each other; and / or, the second edge busbar includes a plurality of second sub-lines arranged sequentially along a first direction, with adjacent second sub-lines disconnected from each other.

2. The solar cell according to claim 1, characterized in that: The distance between adjacent first sub-lines along the first direction is less than the distance between two adjacent first collection grid lines along the first direction; And / or, the distance between adjacent second sub-lines along the first direction is less than the distance between two adjacent second collection grid lines along the first direction.

3. The solar cell according to claim 1, characterized in that: The ratio of the length of the first sub-line to the spacing between adjacent first sub-lines is greater than or equal to 1.5 and less than 100; The ratio of the length of the second sub-line to the spacing between adjacent second sub-lines is greater than or equal to 1.5 and less than 100.

4. The solar cell according to claim 1, characterized in that: The ratio of the spacing between adjacent first sub-lines to the spacing between adjacent first collection grid lines along the first direction is greater than or equal to 0.025 and less than or equal to 0.

75. The ratio of the spacing between adjacent second sub-lines to the spacing between adjacent second collection grid lines along the first direction is greater than or equal to 0.025 and less than or equal to 0.

75.

5. The solar cell according to claim 3, characterized in that: The distance between adjacent first sub-lines along the first direction is greater than or equal to 0.05 mm and less than or equal to 1.5 mm; The distance between adjacent second sub-lines along the first direction is greater than or equal to 0.05 mm and less than or equal to 1.5 mm.

6. The solar cell according to claim 4, characterized in that: The distance between two adjacent first collection grid lines along the first direction is greater than or equal to 0.5 mm and less than or equal to 2 mm; The distance between two adjacent second collection grid lines along the first direction is greater than or equal to 0.5 mm and less than or equal to 2 mm.

7. The solar cell according to any one of claims 1-6, characterized in that: The first surface of the substrate is further provided with a first bus gate line, which extends along a second direction and is electrically connected to the first edge bus gate line; the first surface has a first serial connection area and a second serial connection area arranged alternately along the second direction, the first serial connection area includes a first edge serial connection area, which is the first serial connection area closest to the first edge, and the first edge serial connection area includes a plurality of first external pins, and the first bus gate line is connected to the first external pins; Each of the first busbars is connected to a first sub-line, and each of the first sub-lines is connected to at least one of the first busbars. The first surface of the substrate is further provided with a second bus gate line, which extends along the second direction; the second bus gate line is electrically connected to the second edge bus gate line; the second serial connection area includes a second edge serial connection area, which is the second serial connection area closest to the second edge, and the second edge serial connection area includes a plurality of second external pins; the second bus gate line is connected to the second external pins; Each of the second busbars is connected to a second sub-line, and the second sub-line is connected to at least one of the second busbars.

8. The solar cell according to claim 7, characterized in that: Among the first collection grid lines connected to the same first sub-line, along the first direction, the number of first collection grid lines located on both sides of the first bus grid line connected to the first sub-line are equal or differ by 1; In the second collection grid lines connected to the same second sub-line, along the first direction, the number of second collection grid lines located on both sides of the second busbar connected to the second sub-line are equal or differ by 1.

9. The solar cell according to claim 1, characterized in that: The distance between the first collection grid line connected to the first sub-line and the end of the first sub-line along the first direction is greater than or equal to 50 micrometers; In the second collection grid line connected to the second sub-line, the distance between the second collection grid line closest to the end of the second sub-line and the end of the second sub-line along the first direction is greater than or equal to 50 micrometers.

10. The solar cell according to claim 1, characterized in that: The lengths of the first sub-line and the second sub-line along the first direction are the same.

11. The solar cell according to claim 7, characterized in that: The line width of the first sub-line gradually decreases from the central region of the first sub-line towards both ends; The line width of the second sub-line gradually decreases from the central region of the first sub-line toward both ends.

12. The solar cell according to claim 11, characterized in that: The ratio of the maximum line width to the minimum line width of the first sub-line is greater than or equal to 2 and less than or equal to 10; The ratio of the maximum line width to the minimum line width of the second sub-line is greater than or equal to 2 and less than or equal to 10.

13. The solar cell according to claim 1, characterized in that: The ratio of the linewidth of the first sub-line to the linewidth of the first collection grid line is greater than or equal to 0.1 and less than or equal to 0.9; The ratio of the linewidth of the second sub-line to the linewidth of the second collection grid line is greater than or equal to 0.1 and less than or equal to 0.9; The ratio of the linewidth of the first sub-line to the linewidth of the first busbar is greater than or equal to 0.1 and less than or equal to 0.9; The ratio of the linewidth of the second sub-line to the linewidth of the second busbar is greater than or equal to 0.1 and less than or equal to 0.

9.

14. The solar cell according to claim 7, characterized in that: The ratio of the linewidth of the first busbar to the linewidth of the first collection busbar is greater than or equal to 0.05 and less than or equal to 0.

5. The ratio of the linewidth of the second busbar to the linewidth of the second collection busbar is greater than or equal to 0.05 and less than or equal to 0.

5.

15. A battery assembly, characterized in that, Includes the solar cell described in any one of claims 1-14.

16. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 15.

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