Solar cell, cell string, cell assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a solar cell, a cell string, a cell module and a photovoltaic system. The solar cell comprises a cell substrate, a first main grid line, a second main grid line, a first thin grid line and a second thin grid line, wherein the first main grid line and the second main grid line are arranged on the cell substrate, extend along a first direction and are alternately distributed along a second direction. The two kinds of main grid lines comprise first area sections and second area sections in the first direction, and the first area sections are wider than the second area sections in the second direction. The extension length of the first fine grid lines is smaller than that of the second fine grid lines. Therefore, the second fine grid lines extend longer, and the current collection efficiency is high. The width of the first area section is larger than that of the second area section, the first area section can reduce electric energy loss, and the second area section can save materials and reduce manufacturing cost.

Description

Technical Field

[0001] This application belongs to the technical field of solar cells, and particularly relates to a solar cell, a battery string, a battery module, and a photovoltaic system. Background Art

[0002] Solar energy is a sustainable source of clean energy. Solar cells can convert solar energy into electrical energy by utilizing the photovoltaic effect of the semiconductor p-n junction. Currently, a solar cell is a semiconductor device that directly converts the energy of sunlight into electrical energy. The solar cell utilizes the photovoltaic effect, absorbs photons to excite electrons, and exports these electrons through the built-in electric field to generate current. At this time, the grid lines can collect and transmit the current, thereby realizing the conversion of light energy into electrical energy. However, in the related art, the cross-section of the main grid cannot be too small, otherwise it will lead to a large resistance. Increasing the cross-sectional area of the main grid will increase the material consumption for preparing the main grid, and at the same time, it will cause the fine grid to often not fully cover the silicon substrate, thereby increasing the manufacturing cost of the solar cell and reducing the conversion efficiency of electrical energy. Summary of the Utility Model

[0003] This application provides a solar cell, a battery string, a battery module, and a photovoltaic system, aiming to solve the problems of the conversion efficiency of the energy of the photovoltaic cell and the production cost.

[0004] The solar cell according to the embodiment of this application includes a cell substrate, a first main grid line, a second main grid line, a first fine grid line, and a second fine grid line. The first main grid line and the second main grid line are arranged on the cell substrate. The first main grid line and the second main grid line extend along a first direction and are alternately distributed along a second direction. The first main grid line and the second main grid line include a first region segment and a second region segment along the first direction. The width of the first region segment is greater than the width of the second region segment in the second direction. The first region segment and the second region segment belong to non-welding region segments. The first fine grid line and the second fine grid line are electrically connected to the first main grid line. The first fine grid line is arranged in the first region segment, and the second fine grid line is arranged in the second region segment. The length of the first fine grid line extending towards the second main grid line is less than the length of the second fine grid line extending towards the second main grid line.

[0005] Furthermore, in the second direction, the distances between the ends of the first fine grid line and the second fine grid line and the second main grid line are both 0.35 mm - 0.45 mm.

[0006] Furthermore, the widths of the first main grid line and the second main grid line in the second direction are 10 μm - 300 μm.

[0007] Further, the width of the first region segment in the second direction is 100 μm - 300 μm, and the width of the second region segment in the second direction is 10 μm - 100 μm.

[0008] Further, the solar cell further includes a busbar structure formed on the main grid line.

[0009] Further, the first main grid line further includes a third region segment along the first direction, and the third region segment connects the first region segment and the second region segment respectively. In the first direction, the width of the third region segment in the second direction gradually changes.

[0010] Further, in the first region segment, the width of the first main grid line remains unchanged, and / or the width of the second main grid line remains unchanged.

[0011] Further, in the first region segment, the width of the first main grid line gradually changes, and / or the width of the second main grid line gradually changes.

[0012] Further, the first main grid line and the second main grid line are arranged at equal intervals along the second direction; and / or

[0013] The first fine grid line and the second fine grid line are arranged at equal intervals along the first direction.

[0014] Further, the width of the first fine grid line in the first direction gradually decreases from the side close to the first main grid line along the second direction; and / or

[0015] The width of the second fine grid line in the first direction gradually decreases from the side close to the first main grid line along the second direction.

[0016] An embodiment of the present application further provides a battery string, which is characterized by including the solar cell described in any one of the above.

[0017] An embodiment of the present application further provides a battery module, and the battery module includes the battery string described in the above embodiment.

[0018] An embodiment of the present application further provides a photovoltaic system, and the photovoltaic system includes the battery module described in the above embodiment.

[0019] In the solar cell and photovoltaic module according to the embodiments of the present application, the solar cell includes a cell substrate, a first main grid line, a second main grid line, a first fine grid line, and a second fine grid line. The first main grid line and the second main grid line are disposed on the cell substrate, and the first main grid line and the second main grid line extend along a first direction and are alternately distributed along a second direction. The first main grid line and the second main grid line include a first region segment and a second region segment along the first direction. In the second direction, the width of the first region segment is greater than the width of the second region segment, and the first region segment and the second region segment belong to non-welding region segments; the first fine grid line and the second fine grid line are electrically connected to the first main grid line. The first fine grid line is disposed in the first region segment, and the second fine grid line is disposed in the second region segment; the length of the first fine grid line extending toward the second main grid line is less than the length of the second fine grid line extending toward the second main grid line. In this way, the second fine grid line extends as much as possible on the surface of the cell substrate, which can effectively collect current and has high efficiency. The width of the first region segment is greater than the width of the second region segment. The first region segment can reduce power loss and improve stability, and the second region segment can save materials to reduce the manufacturing cost of the solar cell. Description of the Drawings

[0020] Figure 1 is a partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0021] Figure 2 is another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0022] Figure 3 is yet another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0023] Figure 4 is still another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0024] Figure 5 is a structural schematic diagram of a battery string according to an embodiment of the present application;

[0025] Figure 6 is a structural schematic diagram of a battery module according to an embodiment of the present application;

[0026] Figure 7 is a structural schematic diagram of a photovoltaic system according to an embodiment of the present application.

[0027] Main Element Symbol Description:

[0028] 100, solar cell; 10, cell substrate; 20, first main grid line; 30, second main grid line; 41, first region segment; 42, second region segment; 43, third region segment; 50, first fine grid line; 60, second fine grid line; 70, bus bar structure; 200, battery string; 300, battery module; 400, photovoltaic system. Detailed implementation manners

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0031] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0032] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a connection that can communicate with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0033] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0035] In the related art, solar cells utilize the photovoltaic effect to excite electrons by absorbing photons, and these electrons are guided out to generate current through a built-in electric field. At this time, the grid lines can collect and transmit current, thereby realizing the conversion of light energy into electrical energy. However, in order to meet the highest efficiency of energy conversion, the cross-section of the main grid cannot be too small, otherwise it will lead to a large resistance, and increasing the cross-sectional area of ​​the main grid will increase the material consumption for preparing the main grid, and at the same time, it will cause the fine grid to often not be fully covered on the silicon substrate, thereby increasing the production cost of the solar cell and reducing the conversion efficiency of electrical energy. In this embodiment, the second fine grid line extends as much as possible on the surface of the battery cell substrate, which can effectively collect current and has high efficiency. The width of the first area segment is greater than the width of the second area segment. The first area segment can reduce losses and improve stability, and the second area segment can save materials to reduce the production cost of the solar cell.

[0036] Embodiment 1

[0037] See also Figure 1 and Figure 2, in the solar cell 100 according to the embodiment of the present application, the solar cell 100 includes a cell substrate 10, a first main grid line 20, a second main grid line 30, a first fine grid line 50 and a second fine grid line 60. The first main grid line 20 and the second main grid line 30 are disposed on the cell substrate 10. The first main grid line 20 and the second main grid line 30 extend along a first direction and are alternately distributed along a second direction. The first main grid line 20 and the second main grid line 30 include a first region segment 41 and a second region segment 42 along the first direction. In the second direction, the width of the first region segment 41 is greater than the width of the second region segment 42. The first region segment 41 and the second region segment 42 belong to non-welding region segments. The first fine grid line 50 and the second fine grid line 60 are electrically connected to the first main grid line 20. The first fine grid line 50 is disposed in the first region segment 41, and the second fine grid line 60 is disposed in the second region segment 42. The length of the first fine grid line 50 extending toward the second main grid line 30 is less than the length of the second fine grid line 60 extending toward the second main grid line 30.

[0038] In the solar cell 100 according to the embodiment of the present application, the solar cell 100 includes a cell substrate 10, a first main grid line 20, a second main grid line 30, a first fine grid line 50 and a second fine grid line 60. The first main grid line 20 and the second main grid line 30 are disposed on the cell substrate 10. The first main grid line 20 and the second main grid line 30 extend along a first direction and are alternately distributed along a second direction. The first main grid line 20 and the second main grid line 30 include a first region segment 41 and a second region segment 42 along the first direction. In the second direction, the width of the first region segment 41 is greater than the width of the second region segment 42. The first region segment 41 and the second region segment 42 belong to non-welding region segments. The first fine grid line 50 and the second fine grid line 60 are electrically connected to the first main grid line 20. The first fine grid line 50 is disposed in the first region segment 41, and the second fine grid line 60 is disposed in the second region segment 42. The length of the first fine grid line 50 extending toward the second main grid line 30 is less than the length of the second fine grid line 60 extending toward the second main grid line 30. In this way, the second fine grid line 60 extends as much as possible on the surface of the cell substrate 10, which can effectively collect current and has high efficiency. The width of the first region segment 41 is greater than the width of the second region segment 42. The first region segment 41 can reduce losses and improve stability, and the second region segment 42 can save materials to reduce the manufacturing cost of the solar cell 100.

[0039] Specifically, the first main grid line 20 and the second main grid line 30 are disposed on the battery cell substrate 10 and extend along a first direction, and the first main grid line 20 and the second main grid line 30 are alternately distributed in a second direction. That is to say, a lot of main grid lines with opposite polarities are alternately distributed in the second direction of the battery cell substrate 10. These main grid lines are alternately distributed in the second direction of the battery cell substrate 10 according to the rule of positive, negative, positive, negative. In the embodiment of the present application, the polarities of the first main grid line 20 and the second main grid line 30 are not limited, and "first" and "second" are only used to distinguish the main grid lines of two polarities. In this way, many groups of main grid lines with opposite polarities are alternately distributed in the second direction, which can avoid the reduction of the transmission efficiency due to the too long fine grid lines. Setting multiple main grid lines can shorten the current transmission path in the fine grid lines, thereby improving the photoelectric conversion efficiency.

[0040] Further, the first main grid line 20 includes a first region segment 41 and a second region segment 42, and the first region segment 41 and the second region segment 42 of the first main grid line 20 are distributed along the first direction. Similarly, the second main grid line 30 also includes a first region segment 41 and a second region segment 42, and the first region segment 41 and the second region segment 42 of the second main grid line 30 are also distributed along the first direction. At the same time, the widths of the first region segment 41 and the second region segment 42 in the second direction are different, and the width of the first region segment 41 is greater than that of the second region segment 42, so that the cross-sectional area of the main grid line is generally increased, thereby reducing the resistance and improving the conversion efficiency of electric energy. And the width of the second region segment 42 is smaller than that of the first region segment 41, so that the material consumption for preparing the main grid line will not increase too much, reducing the preparation cost. At the same time, the second region segment 42 with a smaller width will leave enough space for the fine grid lines to cover on the battery cell substrate 10, further improving the conversion efficiency of electric energy.

[0041] In addition, the first region segments 41 and the second region segments 42 of the first main grid line 20 and the second main grid line 30 can be correspondingly arranged, so that the upper ends and the lower ends of the two first region segments 41 in the first direction can be connected by fine grid lines to form a rectangle, and the corresponding ends of the two second region segments 42 can also be connected to form a rectangle. And the first region segment 41 and the second region segment 42 belong to non-welding region segments.

[0042] Furthermore, the first fine grid line 50 and the second fine grid line 60 are both connected to the first main grid line 20 and have the same polarity. The first main grid line 20 can correspond to multiple groups of fine grid lines, and each group can have a first fine grid line 50 and a second fine grid line 60, so that multiple groups of fine grid lines can cover the surface of the battery cell substrate 10. The multiple groups of fine grid lines collect the photo-generated current generated on the battery cell substrate 10 and transmit it to the first main grid line 20.

[0043] Furthermore, the first fine grid line 50 and the second fine grid line 60 extend along the second direction towards the second main grid line 30. Since the first main grid line 20 and the second main grid line 30 are alternately distributed in the second direction of the cell substrate 10, the second main grid line 30 is distributed on both sides of the first main grid line 20, and the first fine grid line 50 and the second fine grid line 60 extend towards the two second main grid lines 30 on both sides of the first main grid line 20. At the same time, the first fine grid line 50 is arranged in the first region segment 41. Since the two first region segments 41 of the first main grid line 20 and the second main grid line 30 are correspondingly arranged and have a larger width, they will occupy more positions, reducing the area that the first fine grid line 50 arranged in the first region segment 41 can cover, thereby reducing the length of the first fine grid line 50. The second fine grid line 60 is arranged in the second region segment 42. Since the two second region segments 42 of the first main grid line 20 and the second main grid line 30 are correspondingly arranged and have a smaller width, they will occupy less area, enabling the second fine grid line 60 to cover more areas, so the length of the second fine grid line 60 can be larger. In this way, the length of the first fine grid line 50 is less than that of the second fine grid line 60. Thus, the larger width of the first region segment 41 of the first main grid line 20 can reduce the resistance and the manufacturing cost, while the longer length of the second fine grid line 60 can ensure the photoelectric conversion efficiency.

[0044] In addition, in the embodiment of the present application, the first region segment 41 and the second region segment 42 belonging to the non-welding region segments mean that neither the first region segment 41 nor the second region segment 42 is directly connected to the solder tape. Or rather, the first region segment 41 and the second region segment 42 are not used for welding the solder tape, and the solder tape can be welded at other positions of the first main grid line 20 and the second main grid line 30. For example, structures such as pads can be arranged on the main grid line, and then the solder tape can be welded to the pads.

[0045] Embodiment 2

[0046] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, in the second direction, the distances from the ends of the first fine grid line 50 and the second fine grid line 60 to the second main grid line 30 are both 0.35 mm - 0.45 mm. For example, in the second direction, the distances from the ends of the first fine grid line 50 and the second fine grid line 60 to the second main grid line 30 can be set to 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm, 0.40 mm, 0.41 mm, 0.42 mm, 0.43 mm, 0.44 mm, 0.45 mm.

[0047] In the embodiment of the present application, the first fine grid line 50 and the second fine grid line 60 extend from the first main grid line 20 along the second direction towards the second main grid line 30. Since the polarities of the first main grid line 20 and the second main grid line 30 are opposite, to avoid short - circuit of the battery substrate 10, the first main grid line 20 and the second main grid line 30 cannot be connected together. Therefore, the ends of the first fine grid line 50 and the second fine grid line 60 connected to the first main grid line 20 should be at a certain distance from the second main grid line 30. For example, the distance between the ends of the first fine grid line 50 and the second fine grid line 60 to the second main grid line 30 can be: 0.35mm, 0.37mm, 0.39mm, 0.41mm, 0.43mm, 0.45mm. In this way, while avoiding direct connection between the first main grid line 20 and the second main grid line 30, the coverage lengths of the first fine grid line 50 and the second fine grid line 60 can be increased as much as possible, improving the photoelectric conversion efficiency while ensuring the safety and reliability of the solar cell 100.

[0048] Of course, in other embodiments, an insulating layer can also be provided between the ends of the first fine grid line 50 and the second fine grid line 60 and the second main grid line 30, and the insulating layer can prevent contact between the fine grid lines and the second main grid line 30.

[0049] Embodiment Three

[0050] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the widths of the first main grid line 20 and the second main grid line 30 in the second direction are 10μm - 300μm.

[0051] Specifically, if the width of the main grid line is too small, the resistance of the solar cell 100 will increase. If the width of the main grid line is too large, it will block more light and occupy the coverage area of the fine grid lines, reducing the photoelectric conversion efficiency and increasing the production cost. Therefore, to ensure the low resistance and electric energy conversion efficiency of the solar cell 100 and control the production cost, the widths of the first main grid line 20 and the second main grid line 30 in the second direction should be limited. For example, the widths of the first main grid line 20 and the second main grid line 30 in the second direction can be 10μm, 30μm, 50μm, 70μm, 90μm, 110μm, 130μm, 150μm, 170μm, 190μm, 210μm, 230μm, 250μm, 270μm, 290μm, 300μm.

[0052] Furthermore, the widths of the first main grid line 20 and the second main grid line 30 in the second direction can be the same or different, which is not specifically limited here to meet different requirements. In one example, the widths of both the first main grid line 20 and the second main grid line 30 in the second direction are 100μm.

[0053] Embodiment Four

[0054] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the width of the first region segment 41 in the second direction is 100 μm - 300 μm, and the width of the second region segment 42 in the second direction is 10 μm - 100 μm.

[0055] In this embodiment, the widths of the first region segment 41 and the second region segment 42 in the second direction are different. The first region segment 41 is wider than the second region segment 42, so the width ranges of the first region segment 41 and the second region segment 42 are different. For example, the width of the first region segment 41 can be: 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, 250 μm, 275 μm, 300 μm; the width of the second region segment 42 can be: 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm. Thus, the width of the first region segment 41 will be greater than that of the second region segment 42.

[0056] Specifically, both the first main grid line 20 and the second main grid line 30 include the first region segment 41 and the second region segment 42. The first region segment 41 and the second region segment 42 are at different positions in the first direction. The first region segment 41 has a larger width and can carry a larger current, while the second region segment 42 has a smaller width, which allows the fine grid lines to extend as much as possible to increase the efficiency of collecting current.

[0057] Embodiment Five

[0058] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the solar cell 100 further includes a busbar structure 70, which is formed on the main grid lines. Exemplarily, the busbar structure 70 can be a welding point (which can also be called a pad point). As a possible implementation manner, the busbar structure 70 can be connected to the first region segment 41.

[0059] Specifically, the polarities of the first main grid line 20 and the second main grid line 30 are opposite. There should be at least two busbar structures 70 (a positive busbar structure and a negative busbar structure) respectively connected to the positive main grid line and the negative main grid line. In this way, the busbar structures 70 at the positive and negative poles of the solar cell 100 can be connected to an external circuit, and the external circuit can be used to store or transmit the electric energy generated by the solar cell 100.

[0060] Exemplarily, the widths of the first region segments 41 of the first main gate line 20 and the second main gate line 30 are relatively large, connecting the busbar structure 70 to the relatively wide first region segments 41. Such relatively wide main gate lines have lower resistance and can carry larger currents, thereby reducing the power loss when the current in the main gate line converges to the busbar structure 70 and improving the current transmission efficiency.

[0061] It can be understood that in the embodiment of the present application, the busbar structure 70 can be disposed at one end of the first region segment 41 away from the second region segment 42.

[0062] As a possible manner, in the embodiment of the present application, the first region segments 41 are disposed at both ends of two adjacent busbar structures 70 of the main gate line, and the second region segments 42 are disposed in the middle of two adjacent busbar structures 70 to ensure stable connection.

[0063] Embodiment Six

[0064] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, the first main gate line 20 further includes a third region segment 43 along the first direction, and the third region segment 43 is respectively connected to the first region segment 41 and the second region segment 42. In the first direction, the width of the third region segment 43 gradually changes in the second direction.

[0065] Specifically, a third region segment 43 is further disposed between the first region segment 41 and the second region segment 42. That is to say, the first region segment 41 and the second region segment 42 are not directly connected, but are connected through the third region segment 43. And since the first region segment 41 is wider than the second region segment 42, the third region segment 43 should be set with a gradually changing width when connecting the first region segment 41 and the second region segment 42 to match the two different-width region segments being connected. For example, the third region segment 43 can be set with a gradually decreasing width from wide to narrow. The wider end of the third region segment 43 is connected to the first region segment 41 and is set to the same width as one end of the first region segment 41, and the narrower end of the third region segment 43 is connected to the second region segment 42 and is set to the same width as one end of the second region segment 42. This makes the width transition of the entire main gate line smoother, and also makes the resistance change inside the main gate line more gentle, increasing the reliability of the main gate line and reducing the differences caused by the width change of the main gate line.

[0066] Embodiment Seven

[0067] Please refer to Figure 2 and Figure 3 , in some alternative embodiments, in the first region segment 41, the width of the first main gate line 20 remains unchanged, and / or the width of the second main gate line 30 remains unchanged.

[0068] Exemplarily, the width of the first region segment 41 of the first main gate line 20 can be fixed, and the width of the first region segment 41 of the second main gate line 30 can also be fixed; or the width of the first region segment 41 of the first main gate line 20 can be fixed, and the width of the first region segment 41 of the second main gate line 30 can be variable; or the width of the first region segment 41 of the first main gate line 20 can be variable, and the width of the first region segment 41 of the second main gate line 30 can be fixed; or the width of the first region segment 41 of the first main gate line 20 can be variable, and the width of the first region segment 41 of the second main gate line 30 can also be variable.

[0069] In this way, wider main gate lines can be set at positions with larger currents, and narrower main gate lines can be set at positions with smaller currents. Whether the width of the first region segment 41 of the main gate line changes can be set according to actual application requirements or process manufacturing capabilities.

[0070] Embodiment VIII

[0071] Please refer to Figure 3 and Figure 4 , in some alternative embodiments, in the first region segment 41, the width of the first main gate line 20 gradually changes, and / or the width of the second main gate line 30 gradually changes.

[0072] Exemplarily, the width of the first region segment 41 of the first main gate line 20 can gradually change, and the width of the first region segment 41 of the second main gate line 30 can also gradually change; or the width of the first region segment 41 of the first main gate line 20 can gradually change, and the width of the first region segment 41 of the second main gate line 30 can be fixed; or the width of the first region segment 41 of the first main gate line 20 can be fixed, and the width of the first region segment 41 of the second main gate line 30 can gradually change.

[0073] In this way, since the first region segment 41 of the main gate line is connected to the bus bar structure 70, the current collected by the main gate line from the fine gate lines converges to the bus bar structure 70 through the first region, such that the current closer to the bus bar structure 70 in the first region segment 41 is larger, while the current at the position of the first region segment 41 far from the bus bar structure 70 is smaller. Thus, it is not necessary to set the width of the first region segment 41 to be fixed, and the change in the width of the first region segment 41 can be set according to the change in current magnitude. In this way, the region of the first region segment 41 close to the bus bar structure 70 can be set wider, and the position of the first region segment 41 far from the bus bar structure 70 can be set narrower, and the first region segment 41 can be set to have a gradually changing width according to the distance from the bus bar structure 70. Such a gradually changing width can save materials and reduce production costs while ensuring low resistance in the first region segment 41.

[0074] Of course, the width of the first region segment 41 on the main grid line with different polarities can also be set to change or the degree and direction of the width gradient can be adjusted according to specific requirements to meet various needs.

[0075] In addition, in some embodiments, the first region segment 41 and the third region segment 43 can be gradually changed with a certain slope, so that the overall main grid line is coordinated and stable, and they can be prepared together during the preparation process. In some embodiments, the first region segment 41, the third region segment 43, and the second region segment 42 can be gradually changed with a certain slope, so that the overall main grid line is coordinated and stable. At this time, the position of the main grid line closer to the middle is narrower, thereby saving materials and reducing the manufacturing cost of the solar cell.

[0076] Embodiment Nine

[0077] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, the first main grid line 20 and the second main grid line 30 are arranged at equal intervals along the second direction; and / or

[0078] The first fine grid line 50 and the second fine grid line 60 are arranged at equal intervals along the first direction.

[0079] Exemplarily, the first main grid line 20 and the second main grid line 30 are arranged at equal intervals along the second direction, and the first fine grid line 50 and the second fine grid line 60 are arranged at equal intervals along the first direction; or the first main grid line 20 and the second main grid line 30 are arranged at equal intervals along the second direction, and the first fine grid line 50 and the second fine grid line 60 are arranged at unequal intervals along the first direction; or the first main grid line 20 and the second main grid line 30 are arranged at unequal intervals along the second direction, and the first fine grid line 50 and the second fine grid line 60 are arranged at equal intervals along the first direction; or the first main grid line 20 and the second main grid line 30 are arranged at unequal intervals along the second direction, and the first fine grid line 50 and the second fine grid line 60 are arranged at unequal intervals along the first direction.

[0080] Exemplarily, the current of the fine grid lines should converge to the main grid line. The equal interval arrangement of the first fine grid line 50 and the second fine grid line 60 can make the distances between adjacent connection points formed by each fine grid line and the main grid line equal, so that the current converging from the fine grid lines to the main grid line accumulates successively with the increase of the connection points; since the equal interval arrangement of the first fine grid line 50 and the second fine grid line 60 makes the distances between adjacent connection points formed by each fine grid line and the main grid line equal, the current in the main grid line that increases and decreases successively with the change in the number of connection points will be approximately the same; in this way, the current magnitude in different region segments of the main grid line can be calculated to facilitate setting the width or the degree of width gradient of the main grid line; in this way, while ensuring the low resistance of the main grid line and enabling the main grid line to carry the corresponding current, the production cost is also kept relatively low.

[0081] Exemplarily, the current in the main grid lines converges to the busbar structure 70 again. The first main grid line 20 and the second main grid line 30 are arranged at equal intervals along the second direction. At the same time, the first fine grid line 50 and the second fine grid line 60 are also arranged at equal intervals. In this way, the number of fine grid lines in the area corresponding to each busbar structure 70 is approximately the same, or rather, the area of the region where the busbar structure 70 collects current is approximately the same.

[0082] It can be understood that as another way, the area of the busbar structure 70 (or rather, the size of the busbar structure 70#A) can change with the change of the area of the region where the current is collected. For example, the area of the region corresponding to the busbar structure 70#A is area #A, and the area of the region corresponding to the busbar structure 70#B is area #B. If area #A is larger than area #B, then the area of the busbar structure 70#A is larger than the area of the busbar structure 70#B. In addition, the first main grid line 20 and the second main grid line 30 can be arranged at unequal intervals along the second direction, or the first fine grid line 50 and the second fine grid line 60 can be arranged at unequal intervals along the first direction. The embodiments of the present application do not limit the intervals of the fine grid lines and the main grid lines to meet various requirements. Of course, in the embodiments of the present application, when the main grid lines and the fine grid lines are arranged at unequal intervals, the size of the busbar structure 70 can also be adjusted correspondingly. Exemplarily, when the busbar structure 70 converges more fine grid lines, the area of the busbar structure 70 itself increases; when the busbar structure 70 converges fewer fine grid lines, the area of the busbar structure 70 itself decreases.

[0083] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, the width of the first fine grid line 50 in the first direction gradually decreases along the second direction from the side close to the first main grid line 20; and / or

[0084] the width of the second fine grid line 60 in the first direction gradually decreases along the second direction from the side close to the first main grid line 20.

[0085] In this way, the conduction of current by the first fine grid line 50 and the second fine grid line 60 is more stable, which can reduce the use of fine grid paste while enhancing the connection stability and reduce the cost.

[0086] Embodiment Ten

[0087] Please refer to Figure 5 , the embodiments of the present application further provide a battery string 200, and the battery string 200 includes the solar cell 100 of any one of the above embodiments.

[0088] In the embodiments of the present application, the battery string 200 can be formed by sequentially connecting a plurality of sheet-shaped solar cells 100 in series and connected through solder tapes and busbars. It can be understood that in the battery string 200, the battery string 200 can include two serially connected solar cells, three serially connected solar cells, or more solar cells. The specific number of solar cells to be connected in series can be determined according to actual usage. In addition, in the embodiments of the present application, the size and type of the solar cell 100 are not limited either. The specifications and sizes of adjacent solar cells can be the same or different to meet different requirements.

[0089] In the embodiments of the present application, the specific connection method of adjacent solar cells is not limited to meet different requirements. In one embodiment, at least a part of the edges of two adjacent solar cells are stacked together; in another embodiment, two adjacent solar cells can be spaced apart. The spacing between two adjacent solar cells is within a suitable range, which can avoid small operating space and high welding difficulty caused by too small a spacing, and can also avoid wasting component space and increasing costs caused by too large a spacing.

[0090] Embodiment XI

[0091] Please refer to Figure 6 , the embodiments of the present application also provide a battery module 300, and the battery module 300 includes the battery string 200 of the above embodiments.

[0092] It can be understood that in such an embodiment, the battery module 300 may further include a frame, a backsheet, a photovoltaic glass, and an encapsulant film. The encapsulant film can be filled between the front and back surfaces of the solar cell 100, the photovoltaic glass, adjacent solar cells, etc. As a filler, it can be a transparent colloid with good light transmittance and anti-aging properties. For example, the encapsulant film can be an EVA encapsulant film or a POE encapsulant film, and the specific selection can be made according to actual situations and is not limited here.

[0093] The photovoltaic glass can cover the encapsulant film on the front surface of the solar cell 100. The photovoltaic glass can be ultra-white glass, which has a high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, the light transmittance of the ultra-white glass can reach more than 92%, and it can protect the solar cell 100 without affecting the efficiency of the solar cell 100 as much as possible. At the same time, the encapsulant film can bond the photovoltaic glass and the solar cell 100 together, and the presence of the encapsulant film can seal and insulate the solar cell 100 and prevent water and moisture.

[0094] The backsheet can be attached to the adhesive film on the back of the solar cell 100. The backsheet can protect and support the solar cell 100, and has reliable insulation, water resistance and aging resistance. There are multiple choices for the backsheet, which can usually be tempered glass, plexiglass, aluminum alloy TPT composite film, etc., and its specific settings can be determined according to specific circumstances and are not limited here. The whole composed of the backsheet, the solar cell 100, the adhesive film and the photovoltaic glass can be arranged on the frame. The frame serves as the main external support structure of the entire battery module 300 and can stably support and install the battery module 300. For example, the battery module 300 can be installed at the required installation position through the frame.

[0095] Embodiment Twelve

[0096] Please refer to Figure 7 , the embodiment of the present application also provides a photovoltaic system 400, and the photovoltaic system 400 includes the battery module 300 of the above embodiment.

[0097] In this embodiment, the photovoltaic system 400 can be applied in a photovoltaic power station, such as a ground power station, a rooftop power station, a water surface power station, etc., and can also be applied to devices or apparatuses that use solar energy for power generation, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system 400 are not limited to this, that is to say, the photovoltaic system 400 can be applied in all fields that require solar power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system 400 can include a photovoltaic array, a busbar box and an inverter. The photovoltaic array can be an array combination of multiple battery modules 300. For example, multiple battery modules 300 can form multiple photovoltaic arrays. The photovoltaic array is connected to the busbar box, and the busbar box can collect the current generated by the photovoltaic array. After the collected current flows through the inverter and is converted into alternating current required by the mains power grid, it is connected to the mains network to achieve solar power supply.

[0098] In the description of this specification, the descriptions with reference to terms such as "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

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

Claims

1. A solar cell, characterized in that: include: Battery cell substrate; A first busbar and a second busbar are arranged on the cell substrate, the first busbar and the second busbar extend along a first direction and are alternately distributed along a second direction, the first busbar and the second busbar include a first area segment and a second area segment along the first direction, the width of the first area segment is greater than the width of the second area segment in the second direction, and the first area segment and the second area segment are non-welding area segments; A first fine gate line and a second fine gate line electrically connected to the first main gate line, the first fine gate line is arranged in a first region segment, and the second fine gate line is arranged in a second region segment; The length of the first thin gate line extending toward the second main gate line is shorter than the length of the second thin gate line extending toward the second main gate line.

2. The solar cell according to claim 1, characterized in that In the second direction, the distances from the end of the first thin gate line and the end of the second thin gate line to the second main gate line are both 0.35 mm-0.45 mm.

3. The solar cell according to claim 1, characterized in that The width of the first main grid line and the second main grid line in the second direction is 10 μm-300 μm.

4. The solar cell according to claim 3, characterized in that: The width of the first region segment in the second direction is 100 μm-300 μm, and the width of the second region segment in the second direction is 10 μm-100 μm.

5. The solar cell according to claim 4, characterized in that: The solar cell further includes a busbar structure formed on the main grid line.

6. The solar cell according to claim 1, characterized in that The first main grid line further includes a third region segment along the first direction, the third region segment respectively connects the first region segment and the second region segment, and in the first direction, the width of the third region segment in the second direction gradually changes.

7. The solar cell according to claim 6, characterized in that: In the first area segment, the width of the first main grid line remains unchanged, and / or the width of the second main grid line remains unchanged.

8. The solar cell according to claim 6, characterized in that: In the first area segment, the width of the first main grid line changes gradually, and / or the width of the second main grid line changes gradually.

9. The solar cell according to claim 1, characterized in that: The first main grid lines and the second main grid lines are arranged at equal intervals along the second direction; and / or The first thin gate lines and the second thin gate lines are arranged at equal intervals along the first direction.

10. The solar cell according to claim 1, characterized in that: The width of the first thin gate line in the first direction gradually decreases along the second direction from a side close to the first main gate line; and / or The width of the second thin gate line in the first direction gradually decreases along the second direction from a side close to the first main gate line.

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

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

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

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