Photovoltaic cell, cell piece and photovoltaic module

Abstract

The application provides a photovoltaic cell, a cell sub-piece and a photovoltaic module, comprising a cell body and a plurality of grid lines, the cell body comprises an edge region and a center region arranged from the edge to the center direction, the grid lines extend along a first direction of the cell body, and the plurality of grid lines are arranged at intervals on the cell body along a second direction of the cell body, the grid lines comprise a seed layer, the seed layer is electrically connected with the cell body, the width of the seed layer in the edge region is greater than the width of the seed layer in the center region, wherein the width of the seed layer is the size of the seed layer in the second direction. In the application, the seed layer in the edge region has a larger surface contact area, thereby providing a larger fault tolerance space, absorbing the alignment deviation generated by the corresponding printing patterns of the upper and lower screen plates, ensuring that the seed layer can have sufficient contact area with the subsequent transmission layer, improving the fill factor, and thereby improving the conversion efficiency of the photovoltaic cell.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cell technology, and in particular to a photovoltaic cell, cell slabs, and photovoltaic module. Background Technology

[0002] In the manufacturing of crystalline silicon solar cells, the metallization process is a crucial step in forming electrodes to collect photocurrent. As the photovoltaic industry continues to demand higher cell efficiency and cost control, optimizing metallization schemes has become a key focus of technological development. Among these issues, problems with screen lifespan or printing progress can lead to abnormal overlap between the seed layer and the transport layer, easily resulting in a reduced fill factor and consequently lower solar cell efficiency. Summary of the Invention

[0003] The purpose of this application is to provide a photovoltaic cell, a cell slab, and a photovoltaic module to solve the problem in the prior art where screen lifespan or printing progress issues lead to abnormal overlap between the seed layer and the transport layer, which easily results in a reduced fill factor and thus reduces the efficiency of the solar cell.

[0004] A first aspect of this application provides a photovoltaic cell, including a cell body and a plurality of grid lines. The cell body includes an edge region and a central region arranged from the edge to the center. The grid lines extend along a first direction of the cell body and are spaced apart along a second direction of the cell body. Each grid line includes a seed layer electrically connected to the cell body. The width of the seed layer in the edge region is greater than the width of the seed layer in the central region, wherein the width of the seed layer is the dimension of the seed layer in the second direction.

[0005] In one possible design, the edge region includes a first region and a second region, the second region being disposed between the first region and the center region, wherein the width of the seed layer in the first region is greater than the width of the seed layer in the second region.

[0006] In one possible design, the width of the seed layer is between 5 μm and 500 μm.

[0007] In one possible design, the seed layer may have a shape that includes one or more of the following: continuous linear, discontinuous linear, and lattice-like.

[0008] In one possible design, the lattice-shaped seed layer includes multiple conductive units, the conductive units being one or more of the following shapes: circular, elliptical, rectangular, or trapezoidal.

[0009] In one possible design, along a second direction of the battery body, the edge regions are located on opposite sides of the central region.

[0010] In one possible design, the edge region surrounds the outer periphery of the central region.

[0011] In one possible design, along the second direction of the battery body, the width of the edge region is a, the total length of the photovoltaic cell is b, and 0 < a / b < 2 / 5.

[0012] In one possible design, the gate line further includes a transmission layer disposed on the side of the seed layer opposite to the battery body, the transmission layer having a width smaller than the width of the seed layer.

[0013] In one possible design, the width of the transmission layer in the edge region is greater than the width of the transmission layer in the center region.

[0014] In one possible design, the width of the transport layer is between 2 μm and 450 μm.

[0015] In one possible design, the width difference between the transport layer and the seed layer is between 0 and 50 μm.

[0016] A second aspect of this application provides a battery segmentation method, including a battery body and a plurality of grid lines. The battery body includes a first side and a second side disposed opposite to each other along a second direction. The grid lines extend along the first direction of the battery body. Along the second direction of the battery body, the plurality of grid lines are spaced apart on the battery body. Each grid line includes a seed layer, which is electrically connected to the battery body. The width of the seed layer on the second side is greater than at least a portion of the width of the seed layer on the first side, wherein the width of the seed layer is the dimension of the seed layer in the second direction.

[0017] In one possible design, along a first direction of the battery body, the battery body further includes a third side and a fourth side disposed opposite to each other, wherein the width of the seed layer disposed at least partially between the third side and the fourth side is smaller than the width of the seed layer on the third side and / or the fourth side.

[0018] In one possible design, the width of the seed layer is between 5 μm and 500 μm.

[0019] In one possible design, the gate line further includes a transmission layer disposed on the side of the seed layer opposite to the battery body, the transmission layer having a width smaller than the width of the seed layer.

[0020] In one possible design, the width of the transmission layer on the second side 4 is greater than the width of at least a portion of the transmission layer on the first side.

[0021] In one possible design, the width of the transport layer is between 2 μm and 450 μm.

[0022] In one possible design, the width difference between the transport layer and the seed layer is between 0 and 50 μm.

[0023] A third aspect of this application provides a photovoltaic module, comprising: A battery string, wherein the battery string is formed by connecting multiple photovoltaic cells as described in any of the above embodiments; and / or, the battery string is formed by connecting multiple battery segments as described in any of the above embodiments; Encapsulation layer, the encapsulation layer being used to cover the surface of the battery string; A cover plate for covering the surface of the encapsulation layer away from the battery string.

[0024] The technical solution provided in this application can achieve the following beneficial effects: In this application, the width of the seed layer in the edge region is greater than that in the center region, thereby enabling the seed layer in the edge region to have a larger surface contact area. This provides a larger tolerance space for the subsequent alignment printing of the transport layer, absorbs the alignment deviation caused by the printing patterns of the upper and lower screens, and ensures that the seed layer can overlap with the subsequent transport layer with sufficient contact area. This ensures the stability of the contact resistance in the edge region, improves the fill factor of the photovoltaic cell, and thus improves the conversion efficiency of the photovoltaic cell.

[0025] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0026] Figure 1 A schematic diagram of the structure of the photovoltaic cell provided in this application in a specific embodiment; Figure 2 for Figure 1 A cross-sectional view along the AA direction; Figure 3 A schematic diagram of the structure of the photovoltaic cell provided in this application in another specific embodiment; Figure 4 A schematic diagram of the structure of the photovoltaic cell provided in this application in another specific embodiment; Figure 5 A schematic diagram of the structure of the photovoltaic cell provided in this application in another specific embodiment; Figure 6 A schematic diagram of the structure of the photovoltaic cell provided in this application in another specific embodiment; Figure 7A schematic diagram of the structure of the photovoltaic cell provided in this application in another specific embodiment; Figure 8 A schematic diagram of the structure of the photovoltaic cell provided in this application in another specific embodiment; Figure 9 for Figure 8 A schematic diagram of the structure along the BB direction; Figure 10 A schematic diagram of the structure of the battery segmentation provided in this application in a specific embodiment; Figure 11 A schematic diagram of the structure of the battery segmentation provided in this application in another specific embodiment; Figure 12 A schematic diagram of the structure of the battery segmentation provided in this application in another specific embodiment; Figure 13 for Figure 12 Schematic diagram of the structure along the CC direction; Figure 14 This is a schematic diagram of the structure of the photovoltaic module provided in this application.

[0027] Figure label: 100 - Photovoltaic cell; 10 - Cell segmentation; 1-Battery body; 11-Edge region; 111-First region; 112-Second region; 12-Central region; 13-First side; 14-Second side; 15-Third side; 16-Fourth side; 2-Gate line; 21-Seed layer; 211-Conducting cell; 22-Transport layer; 110-battery string; 120 - Encapsulation layer; 130 - Cover plate; X - First direction; Y - Second direction; Z - Third direction.

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0030] In the description of this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0032] In the description of this specification, it should be understood that the directional terms such as "upper" and "lower" used in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0033] In the manufacturing of crystalline silicon solar cells, the metallization process is a crucial step in forming electrodes to collect photocurrent. As the photovoltaic industry continues to demand higher cell efficiency and cost control, optimizing metallization schemes has become a key focus of technological development. Among these issues, problems with screen lifespan or printing progress can lead to abnormal overlap between the seed layer and the transport layer, easily resulting in a reduced fill factor and consequently lower solar cell efficiency.

[0034] To this end, embodiments of this application provide a photovoltaic cell, a cell segment, and a photovoltaic module to improve the fill factor, thereby increasing the efficiency of the photovoltaic cell and cell segment. This photovoltaic cell and cell segment can be applied to various cell structures, including but not limited to tunnel oxide passivated contact (TOPCon), interdigitated back contact (IBC), and passivated emitter rear cell (PERC), etc., without limitation.

[0035] The battery slabs can be cut from photovoltaic cells. Specifically, photovoltaic cells can be 1-slab, 2-slab, 3-slab, 4-slab, etc., and the specific configuration can be set according to actual needs, without limitation here. In some other embodiments, the battery slabs can also be uncut cells.

[0036] like Figures 1-3 As shown, the photovoltaic cell 100 includes a cell body 1 and multiple grid lines 2 disposed on the cell body 1.

[0037] The battery body 1 includes an edge region 11 and a central region 12, with the edge region 11 and the central region 12 arranged from the edge to the center on the battery body 1. The battery body 1 serves as the semiconductor substrate of the battery. The battery body 1 is a silicon wafer used to fabricate a TOPCon battery, undergoing processes such as cleaning and texturing, boron diffusion to form the emitter, and deposition of a tunneling oxide layer and a polycrystalline silicon layer on the back side to form a passivation contact structure. Alternatively, the battery body 1 can be a silicon wafer used to fabricate a BC battery or other crystalline silicon batteries. For ease of description, the width direction of the battery body 1 is defined as the first direction X, the length direction of the battery body 1 is defined as the second direction Y, and the thickness direction of the battery body 1 is defined as the third direction Z.

[0038] The grid line 2 is used to collect photogenerated carriers and connect to an external circuit. The grid line 2 extends along a first direction X of the battery body 1 and along a second direction Y of the battery body 1, with multiple grid lines 2 spaced apart on the battery body 1. Each grid line 2 includes a seed layer 21, which is electrically connected to the battery body 1. The width of the seed layer 21 in the edge region 11 is greater than the width of the seed layer 21 in the central region 12. The width of the seed layer 21 is its dimension in the second direction Y.

[0039] In screen printing, a multi-layer printing structure is typically used, where a transport layer is printed on the seed layer of the grid lines to form the grid structure through a "line-on-line" method. However, during long-term printing, factors such as changes in screen tension, wear, deformation due to outward expansion, or printing misalignment can easily lead to misalignment of the printed patterns on the upper and lower screen layers. This results in abnormal overlap between the seed layer and the transport layer. Furthermore, due to factors such as screen tension distribution and squeegee pressure, the alignment accuracy of the printed patterns in the edge areas of photovoltaic cells is usually lower than that in the center areas.

[0040] In this embodiment, as Figures 1-3As shown, the width of the seed layer 21 in the edge region 11 is greater than the width of the seed layer 21 in the central region 12, thereby enabling the seed layer 21 in the edge region 11 to have a larger surface contact area. This provides a larger tolerance space for the subsequent alignment printing of the transmission layer 22, absorbs the alignment deviation caused by the printing patterns of the upper and lower screens, and ensures that the seed layer 21 can overlap with the subsequent transmission layer 22 with sufficient contact area. This ensures the stability of the contact resistance in the edge region, improves the fill factor of the photovoltaic cell 100, and thus improves the conversion efficiency of the photovoltaic cell 100.

[0041] Along a third direction Z of the battery body 1, the battery body 1 has a first surface and a second surface disposed opposite to each other. Exemplarily, the first surface is the light-receiving surface, i.e., the front surface; the second surface is the back surface, i.e., the back surface. Alternatively, the first surface is the back surface, and the second surface is the light-receiving surface. It is understood that the light-receiving surface refers to a surface used to receive sunlight. The back surface is another surface disposed opposite to the light-receiving surface. In some embodiments, the back surface can also be used to receive sunlight. The grid lines 2 can be disposed on the first surface and / or the second surface of the battery body 1, without limitation.

[0042] In one specific embodiment, such as Figure 4 As shown, the width of the seed layer 21 in the edge region 11 and the center region 12 increases along the direction from the center region 12 to the edge region 11, that is, the width of the seed layer 21 gradually increases from the center region 12 to the edge region 11.

[0043] In this embodiment, as the width of the seed layer 21 gradually increases from the central region 12 to the edge region 11, the contact area of ​​the seed layer 21 also gradually increases. This gradually increases the tolerance space provided for the subsequent alignment printing of the transmission layer 22, and the ability to absorb the alignment deviations caused by the printing patterns corresponding to the upper and lower screens is also stronger. Thus, while ensuring that the seed layer 21 and the transmission layer 22 have sufficient contact area, it can avoid wasting the printing paste of the seed layer 21 and save costs.

[0044] In another specific embodiment, such as Figure 5 As shown, the width of the seed layer 21 in the edge region 11 increases in the direction away from the central region 12, that is, the width of the seed layer 21 in the edge region 11 gradually increases in the direction away from the central region 12.

[0045] In this embodiment, the width of the seed layer 21 in the edge region 11 gradually increases in the direction away from the central region 12. This ensures sufficient contact area between the seed layer 21 and the transport layer 22 while avoiding waste of printing paste for the seed layer 21, thus saving costs. Furthermore, since the alignment accuracy of the screen-printed pattern in the central region 12 is high, making the width of the seed layer 21 in the central region 12 uniform ensures sufficient contact area between the seed layer 21 and the transport layer 22 while further reducing the amount of printing paste for the seed layer 21, thus saving manufacturing costs.

[0046] In one specific embodiment, such as Figure 6 As shown, the edge region 11 includes a first region 111 and a second region 112. The second region 112 is located between the first region 111 and the center region 12. The width of the seed layer 21 in the first region 111 is greater than the width of the seed layer 21 in the second region 112.

[0047] In this embodiment, the accuracy of the screen-printed pattern tends to decrease significantly near the edge of the battery body 1. By dividing the edge region 11 into a first region 111 away from the central region 12 and a second region 112 closer to the central region 12, and making the width of the seed layer 21 in the first region 111 greater than the width of the seed layer 21 in the second region 112, the seed layer 21 in the first region 111 can better absorb the alignment deviation caused by the corresponding printed patterns of the upper and lower screens, thus avoiding abnormal overlap between the seed layer 21 and the transport layer 22 in this region. Setting the width of the seed layer 21 in the second region 112 to be smaller can avoid waste of printing paste for the seed layer 21, thereby saving costs.

[0048] In this embodiment, the seed layers 21 in the first region 111 can be set to be the same, and / or the seed layers 21 in the second region 112 can be set to be the same, so as to reduce the preparation difficulty and save the preparation cost. In other embodiments, the seed layers 21 in the first region 111 can gradually increase in size along the direction away from the central region 12, so as to further save the printing paste of the seed layers 21.

[0049] In the above embodiments, as Figures 1-6 As shown, along the second direction Y of the battery body 1, the edge region 11 can be disposed on opposite sides of the central region 12, so that the battery body 1 can be divided along the second direction Y as follows: Figures 1-5 The three areas shown, or, as Figure 6As shown, the edge region 11 includes two regions, namely the first region 111 and the second region 112, thereby dividing the battery body 1 into five regions to facilitate the configuration of the fault tolerance space of the seed layer 21 in different regions according to actual needs. In some other embodiments, the edge region 11 may also include three or four regions, etc., and the multiple regions may be arranged sequentially in a direction away from the central region 12. The specific arrangement can be set according to actual needs and is not limited here.

[0050] In another specific embodiment, such as Figure 7 As shown, the edge region 11 can also surround the outer periphery of the central region 12, so that the battery body 1 can be divided into the central region 12 and a plurality of annular edge regions 11 sequentially segmented outward from the central region 12. For example, the edge region 11 can be divided into a second region 112 and a first region 111 sequentially segmented around the central region 12. In some other embodiments, the edge region 11 can also be divided into three annular regions, four annular regions, etc. sequentially segmented around the central region 12, which can be set according to actual needs and is not limited here. Among them, the seed layer 21, which is at least partially located in the central region 12, has its two ends along the first direction X located in the edge region 11, that is, the width of the two ends of the seed layer 21 along the first direction X is greater than the width of its middle position, so as to ensure that even if the offset occurs along the first direction X during the screen printing process, the seed layer 21 at both ends can still absorb the alignment deviation caused by the printing pattern corresponding to the upper and lower screen plates, further improving the fault tolerance space of the seed layer 21.

[0051] In one specific embodiment, such as Figure 3 As shown, along the second direction Y of the battery body 1, the width of the edge region 11 is a, and the total length of the photovoltaic cell 100 is b, where 0 < a / b < 2 / 5. For example, the ratio a / b of the width a of the edge region 11 to the total length b of the photovoltaic cell 100 can be 1 / 8, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 3 / 8, 2 / 5, etc. Of course, the ratio a / b of the width a of the edge region 11 to the total length b of the photovoltaic cell 100 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0052] If the edge region 11 is not provided, during the screen printing process, the printing patterns corresponding to the upper and lower screen plates near the edge of the battery body 1 will have a large alignment deviation, which is likely to cause abnormal overlap between the seed layer 21 and the transmission layer 22, reducing the fill factor and decreasing the conversion efficiency of the photovoltaic cell 100. If the ratio a / b of the width a of the edge region 11 to the total length b of the photovoltaic cell 100 is large, that is, the proportion of the edge region 11 in the total length of the photovoltaic cell 100 is too large, the proportion of the central region 12 will be too low, which will easily increase the paste cost of the grid line 2. In addition, there are more seed layers 21 with a larger width in the edge region 11, which can easily cause an excessively large shading area on the battery body 1, reducing the conversion efficiency of the photovoltaic cell 100.

[0053] Therefore, when the width a of the edge region 11 and the total length b of the photovoltaic cell 100 satisfy 0 < a / b < 2 / 5 along the second direction Y of the battery body 1, the seed layer 21 in the edge region 11 can absorb the printing pattern corresponding to the upper and lower screens and produce a large alignment deviation, thereby improving the fill factor. It can also avoid having too many wide seed layers 21 in the edge region 11, reduce shading loss, and improve the conversion efficiency of the photovoltaic cell 100.

[0054] In this embodiment, along the second direction Y, the width 'a' of the central region 12 relative to the two side edge regions 11 can be the same to facilitate fabrication. In some other embodiments, the width 'a' of the central region 12 relative to the two side edge regions 11 can also be different to increase design flexibility.

[0055] For example, such as Figure 3 As shown, taking a photovoltaic cell 100 with a total length of 213mm in the second direction Y as an example, the area in the range of 0~60mm and the area in the range of 150mm~213mm along the second direction Y are the edge regions 11. The seed layer 21 in the edge region 11 can absorb the large alignment deviation of the printed patterns corresponding to the upper and lower screens, improve the fill factor, and improve the conversion efficiency of the photovoltaic cell 100.

[0056] In one specific embodiment, the shape of the seed layer 21 includes one or more of continuous linear, discontinuous linear, and lattice shapes. The shape of the seed layer 21 is its shape in the third direction Z.

[0057] In this embodiment, by including one or more of the following shapes for the seed layer 21: continuous linear, discontinuous linear, and lattice-shaped, the design freedom of the photovoltaic cell 100 can be improved. When the seed layer is a continuous linear structure, the contact between the seed layer 21 and the cell body 1 is more uniform, which is beneficial for continuous current transmission. When the seed layer 21 is discontinuous linear or lattice-shaped, the use of seed layer 21 material can be reduced, saving paste, lowering manufacturing costs, and reducing the risk of grid breakage during printing, thereby improving the performance of the grid lines 2.

[0058] For example, such as Figure 1 As shown, the seed layer 21 is a continuous linear structure, that is, the seed layer 21 is an uninterrupted continuous linear structure along its extension direction (first direction X), which is conducive to the continuous transmission of current.

[0059] For example, such as Figures 3-7 As shown, the seed layer 21 has a lattice structure, which includes multiple conductive units 211. The multiple conductive units 211 are arranged at intervals along the extension direction (first direction X) of the seed layer 21. Since the seed layer 21 only needs to achieve electrical contact with the battery body 1 at discrete points and does not need to be continuously covered, the material used in the seed layer 21 can be reduced, thus saving manufacturing costs.

[0060] The conductive unit 211 can be one or more of the following shapes: circular, elliptical, rectangular, or trapezoidal. When the conductive unit 211 is circular, its smooth edges provide good structural stability, which is beneficial for improving the performance of the grid line 2. When the conductive unit 211 is elliptical, it increases the contact area between the conductive unit 211 and the battery body 1, thereby reducing contact resistance. When the conductive unit 211 is rectangular or trapezoidal, its neat edges improve the connection with the transmission layer 22. Of course, the conductive unit 211 can also be other shapes, depending on actual needs.

[0061] For example, such as Figures 3-7 As shown, the conductive unit 211 is circular, which makes the contact area and current distribution of the conductive unit 211 more uniform. The edges of the circular conductive unit 211 are smooth, so even if the screen is slightly deformed during printing, the area change of the circular conductive unit 211 is relatively small. The structure of the seed layer 21 is more stable, which is beneficial to improving the performance of the grid line 2.

[0062] In some embodiments, conductive units 211 of different shapes can be implemented by screen printing of stencil patterns. In some other embodiments, conductive units 211 of different shapes can also be implemented by laser transfer of spot shapes or inkjet printing of droplet shapes.

[0063] In one specific embodiment, such as Figure 1 , Figure 2 , Figure 8 and Figure 9 As shown, the gate line 2 also includes a transmission layer 22, which is disposed on the side of the seed layer 21 away from the battery body 1.

[0064] The seed layer 21 forms an ohmic contact with the battery body 1. The material of the seed layer 21 can be a silver-containing paste. The transport layer 22 is printed onto the side of the seed layer 21 facing away from the battery body 1, and is used to screen and transport photogenerated carriers. The material of the transport layer 22 can be silver-coated copper paste, silver-coated nickel paste, or a mixture of the above pastes. In some embodiments, the material of the seed layer 21 is silver paste, so as to form a high-quality ohmic contact with the battery body 1 while improving the conversion efficiency of the photovoltaic cell 100. By printing the transport layer 22, which is made of base metals such as silver-coated copper paste or silver-coated nickel paste, onto the seed layer 21 formed by silver paste, the transport layer has high conductivity while reducing the cost of the grid line 2.

[0065] Among them, such as Figure 1 , Figure 2 , Figure 8 and Figure 9 The width of the transmission layer 22 is smaller than the width of the seed layer 21, that is, the size of the transmission layer 22 in the second direction Y is smaller than the size of the seed layer 21 in the second direction.

[0066] As mentioned earlier, during long-term printing, factors such as changes in screen tension, wear, deformation due to outward expansion, or printing offset can easily lead to alignment deviations between the printed patterns of the upper and lower screen layers, resulting in abnormal overlap between the seed layer 21 and the transmission layer 22. If the width of the transmission layer 22 is greater than or equal to the width of the seed layer 21, once the transmission layer 22 shifts, it is easy for the transmission layer 22 to come into contact with the battery body 1, affecting the conductivity.

[0067] In this embodiment, the width of the transport layer 22 is smaller than the width of the seed layer 21. Even when the transport layer 22 is slightly offset, it can still be printed on the side of the seed layer 21 away from the battery body 1, avoiding contact between the transport layer 22 and the battery body 1, thereby improving conductivity and fabrication yield.

[0068] In one specific embodiment, such as Figure 9 As shown, the width of the transmission layer 22 in the edge region 11 is greater than the width of the transmission layer 22 in the center region 12.

[0069] As mentioned earlier, due to factors such as the tension distribution of the stencil and the pressure of the squeegee, the alignment accuracy of the printed pattern in the edge area of ​​the photovoltaic cell is usually lower than that in the center area.

[0070] In this embodiment, by setting the width of the transmission layer 22 in the edge region 11 to be greater than the width of the transmission layer 22 in the center region 12, the contact area between the transmission layer 22 and the seed layer 21 in the edge region 11 can be increased, thereby improving the fill factor of the photovoltaic cell 100 and thus improving the conversion efficiency of the photovoltaic cell 100.

[0071] In some embodiments, such as Figure 9 As shown, the width of the transfer layer 22 in the edge region 11 and the center region 12 increases along the direction from the center region 12 to the edge region 11. That is, the width of the transfer layer 22 gradually increases from the center region 12 to the edge region 11. This ensures that the transfer layer 22 and the seed layer 21 have sufficient contact area while avoiding waste of printing transfer layer 22 paste and saving preparation costs.

[0072] In other embodiments, the width of the transfer layer 22 in the edge region 11 increases gradually away from the central region 12. This ensures sufficient contact area between the transfer layer 22 and the seed layer 21 while avoiding waste of printing paste for the transfer layer 22, thus saving manufacturing costs. Furthermore, since the alignment accuracy of the screen-printed pattern in the central region 12 is high, maintaining a uniform width for the transfer layer 22 in the central region 12 ensures sufficient contact area between the seed layer 21 and the transfer layer 22, further reducing the amount of printing paste for the transfer layer 22 and saving manufacturing costs.

[0073] In other embodiments, such as Figure 1 and Figure 1 As shown, the width of the transport layer 22 is the same on the battery body 1 to reduce the difficulty of preparation, save the slurry of the transport layer 22, and improve the preparation efficiency.

[0074] In one specific embodiment, the shape of the transmission layer 22 includes one or more of continuous linear and discontinuous linear shapes. The shape of the transmission layer 22 is its shape in the third direction Z.

[0075] For example, such as Figure 1 As shown, the seed layer 21 is a continuous line, which makes the contact between the seed layer 21 and the battery body 1 more uniform. The transmission layer 22 is also printed as a continuous line on the seed layer 21, which can improve the reliability of current transmission and ensure the performance of the grid line 2.

[0076] For example, such as Figure 4 and 8As shown, the seed layer 21 is dot-matrix shaped and includes multiple conductive units 211. The multiple conductive units 211 are arranged at intervals along the first direction X, which can save printing paste on the seed layer 21. The transmission layer 22 is printed as a continuous line on the seed layer 21, thereby connecting the various conductive units 211 of the seed layer 21 to form a continuous conductive channel, which can achieve continuous current transmission while saving paste.

[0077] In one specific embodiment, such as Figure 9 As shown, the width D of the seed layer 21 is between 5μm and 500μm. For example, the width D of the seed layer 21 can be 5μm, 10μm, 50μm, 100μm, 200μm, 300μm, 400μm, or 500μm, etc. Of course, the width D of the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0078] If the width D of the seed layer 21 is too small, for example, less than 5 μm, the seed layer 21 is too thin, resulting in a small contact area with the battery body 1, weak adhesion, and a tendency for the grid lines 2 to detach, leading to low reliability. Furthermore, an excessively thin seed layer 21 increases its contact resistance with the battery body 1, hindering current collection and reducing conductivity. Additionally, an excessively thin seed layer 21 places extremely high demands on the screen printing plate, paste, and process control, easily increasing manufacturing costs. Moreover, an excessively thin seed layer 21 is more prone to grid breakage, affecting the performance of the grid lines 2.

[0079] If the width D of the seed layer 21 is too large, for example, greater than 500 μm, then the seed layer 21 is too thin, which can easily increase the shading area of ​​the battery body 1, thereby reducing the conversion efficiency of the photovoltaic cell 100.

[0080] Therefore, when the width D of the seed layer 21 is between 5μm and 500μm, the width of the seed layer 21 is moderate, so that its contact area with the battery body 1 is moderate, avoiding large-area obstruction of the surface of the battery body 1. While having high conductivity, it makes the grid lines 2 less prone to falling off and grid breakage, improving reliability. It can also reduce the requirements for screen printing plate, paste and process control, and reduce manufacturing costs.

[0081] In some embodiments, such as Figure 9 As shown, the width D of the seed layer 21 can be between 10μm and 50μm. For example, the width D of the seed layer 21 can be 10μm, 14μm, 15μm, 20μm, 25μm, 30μm, 40μm, or 50μm, etc. Of course, the width D of the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0082] In this embodiment, when the width D of the seed layer 21 is between 10μm and 50μm, the connection reliability between the seed layer 21 and the battery body 1 can be guaranteed and good conductivity can be achieved, while further reducing shading loss and improving the conversion efficiency of the photovoltaic cell 100.

[0083] In one specific embodiment, such as Figure 9 As shown, the width d of the transmission layer 22 is between 2μm and 450μm. For example, the width d of the transmission layer can be 2μm, 5μm, 40μm, 100μm, 200μm, 300μm, 400μm, or 450μm, etc. Of course, the width d of the transmission layer 22 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0084] If the width d of the transmission layer 22 is too small, for example, less than 2μm, then the transmission layer 22 is too thin, which places extremely high demands on the screen printing plate, paste, and process control, and easily increases manufacturing costs. If the width d of the transmission layer 22 is too large, for example, greater than 450μm, then the transmission layer 22 is too wide, which easily increases its shading area on the battery body 1, reduces the conversion efficiency of the photovoltaic cell 100, and increases the paste cost.

[0085] Therefore, when the width d of the transmission layer 22 is between 2μm and 450μm, the width of the transmission layer 22 is moderate, which can reduce the shading area of ​​the battery body 1, improve the conversion efficiency of the photovoltaic cell 100, and reduce the requirements for screen printing plate, paste and process control, thereby reducing manufacturing costs.

[0086] In some embodiments, such as Figure 9 As shown, the width d of the transmission layer 22 can be between 5μm and 40μm. For example, the width d of the transmission layer 22 can be 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, or 40μm, etc. Of course, the width d of the transmission layer 22 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0087] In this embodiment, when the width d of the transmission layer 22 is between 5μm and 40μm, it can ensure a reliable connection between the transmission layer 22 and the seed layer 21, and at the same time have better current collection capability, it further reduces shading loss and improves the conversion efficiency of the photovoltaic cell 100.

[0088] In one specific embodiment, such as Figure 9As shown, the width difference between the transport layer 22 and the seed layer 21 is between 0 and 50 μm. For example, the width difference between the transport layer 22 and the seed layer 21 can be 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 35 μm, or 40 μm, etc. Of course, the width difference between the transport layer 22 and the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0089] If the widths of the transmission layer 22 and the seed layer 21 are the same, the printing process requires extremely high precision. However, if the width difference between the transmission layer 22 and the seed layer 21 is too large, the seed layer 21 needs to be set wider, which can easily increase the light-shielding area of ​​the battery body 1 and reduce the conversion efficiency of the photovoltaic cell 100.

[0090] Therefore, when the width difference between the transmission layer 22 and the seed layer 21 is between 0 and 50 μm, the light shading loss can be reduced, ensuring that the transmission layer 22 and the seed layer 21 have sufficient contact area. This allows for efficient and full current collection while reducing the requirements for printing process precision, lowering manufacturing difficulty, and improving manufacturing yield.

[0091] In some embodiments, such as Figure 9 As shown, the width difference between the transmission layer 22 and the seed layer 21 can be between 0 and 10 μm. For example, the width difference between the transmission layer 22 and the seed layer 21 can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, etc. Of course, the width difference between the transmission layer 22 and the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0092] In this embodiment, when the width difference between the transmission layer 22 and the seed layer 21 is between 0 and 10 μm, it can ensure that the transmission layer 22 and the seed layer 21 have sufficient contact area, improve the fill factor, and improve the conversion efficiency of the photovoltaic cell 100.

[0093] like Figure 10 As shown, this application also provides a battery cell 10. As mentioned above, the battery cell 10 can be cut from the photovoltaic cell 100. In some other embodiments, the battery cell 10 can also be an uncut cell.

[0094] The battery cell 10 includes a battery body 1 and multiple grid lines 2. The battery body 1 has the same structure as the battery body of the photovoltaic cell 100 described above, and will not be described again here.

[0095] The battery body 1 includes a first side 13 and a second side 14 disposed opposite to each other along the second direction Y. For example, when the battery segment 10 is cut from the photovoltaic cell 100, along the second direction Y, the first side 13 is the side of the battery segment 10 closest to the central region 12 of the photovoltaic cell 100, and the second side 14 is the side of the battery segment 10 furthest from the central region 12 of the photovoltaic cell 100. For example, when the battery segment 10 is an uncut cell, the first side 13 and the second side 14 are opposite sides of the battery body 1 along the second direction Y.

[0096] The grid lines 2 extend along a first direction X of the battery body 1 and along a second direction Y of the battery body 1, with multiple grid lines 2 spaced apart on the battery body 1. Each grid line 2 includes a seed layer 21, which is electrically connected to the battery body 1. The width of the seed layer 21 on the second side 14 is greater than the width of at least a portion of the seed layer 21 on the first side 13, wherein the width of the seed layer 21 is its dimension in the second direction Y.

[0097] In this embodiment, the width of the seed layer 21 on the second side 14 is greater than the width of the seed layer 21 on the first side 13, thereby enabling the seed layer 21 on the second side 14 to have a larger surface contact area. This provides a larger tolerance space for the subsequent alignment printing of the transmission layer 22, absorbs the alignment deviation caused by the printing patterns corresponding to the upper and lower screens, and ensures that the seed layer 21 can overlap with the subsequent transmission layer 22 with sufficient contact area. This ensures the stability of the contact resistance in the edge area, improves the fill factor of the battery segment 10, and thus improves the conversion efficiency of the battery segment 10.

[0098] In one specific embodiment, such as Figure 10 As shown, the width of the seed layer 21 increases from the first side 13 to the second side 14. That is, the width of the seed layer 21 gradually increases from the first side 13 to the second side 14, thereby gradually improving the ability of the seed layer 21 to absorb the alignment deviation caused by the printing patterns of the upper and lower screens. This ensures that the seed layer 21 and the transport layer 22 have sufficient contact area while avoiding waste of printing paste in the seed layer 21 and saving costs.

[0099] In one specific embodiment, such as Figure 11 As shown, along the first direction X of the battery body 1, the battery body 1 also includes a third side 15 and a fourth side 16 disposed opposite to each other. The width of the seed layer 21 disposed at least partially between the third side 15 and the fourth side 16 is smaller than the width of the seed layer 21 of the third side 15 and / or the fourth side 16. Even if an offset occurs along the first direction X during the screen printing process, the seed layers 21 at both ends can still absorb the alignment deviation caused by the printing patterns corresponding to the upper and lower screen plates, further improving the fault tolerance space of the seed layer 21.

[0100] like Figure 12 As shown, the grid line 2 also includes a transport layer 22, which is disposed on the side of the seed layer 21 facing away from the cell body 1. The seed layer 21 forms an ohmic contact with the cell body 1, and the transport layer 22 is printed on the side of the seed layer 21 facing away from the cell body 1, for screening and transporting photogenerated carriers. The materials of the seed layer 21 and the transport layer 22 of the cell slab 10 can be the same as those of the seed layer 21 and the transport layer 22 of the photovoltaic cell 10, achieving the same technical effects, and will not be described again here.

[0101] In one specific embodiment, the width of the transmission layer 22 is smaller than the width of the seed layer 21, that is, the size of the transmission layer 22 in the second direction Y is smaller than the size of the seed layer 21 in the second direction.

[0102] In this embodiment, the width of the transport layer 22 is smaller than the width of the seed layer 21. Even when the transport layer 22 is slightly offset, it can still be printed on the side of the seed layer 21 away from the battery body 1, avoiding contact between the transport layer 22 and the battery body 1, thereby improving conductivity and fabrication yield.

[0103] In one embodiment, the width of the transmission layer 22 on the second side 14 is greater than the width of at least a portion of the transmission layer 22 on the first side 13.

[0104] In this embodiment, by setting the width of the transmission layer 22 on the second side 14 to be greater than the width of the transmission layer 22 on the first side 13, the contact area between the transmission layer 22 on the second side 14 and the seed layer 21 can be increased, thereby improving the fill factor of the battery segment 10 and thus improving the conversion efficiency of the battery segment 10.

[0105] In one specific embodiment, such as Figure 13 As shown, the width D of the seed layer 21 is between 5μm and 500μm. For example, the width D of the seed layer 21 can be 5μm, 10μm, 50μm, 100μm, 200μm, 300μm, 400μm, or 500μm, etc. Of course, the width D of the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0106] In this embodiment, when the width D of the seed layer 21 is between 5μm and 500μm, the width of the seed layer 21 is moderate, so that its contact area with the battery body 1 is moderate, avoiding large-area obstruction of the surface of the battery body 1. While having high conductivity, it makes the grid lines 2 less prone to falling off and grid breakage, improving reliability. It can also reduce the requirements for screen printing stencils, pastes and process control, and reduce manufacturing costs.

[0107] In some embodiments, such as Figure 13As shown, the width D of the seed layer 21 can be between 10μm and 50μm. For example, the width D of the seed layer 21 can be 10μm, 14μm, 15μm, 20μm, 25μm, 30μm, 40μm, or 50μm, etc. Of course, the width D of the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0108] In this embodiment, when the width D of the seed layer 21 is between 10μm and 50μm, the connection reliability between the seed layer 21 and the battery body 1 can be guaranteed and good conductivity can be achieved, while further reducing shading loss and improving the conversion efficiency of the photovoltaic cell 100.

[0109] In one specific embodiment, such as Figure 13 As shown, the width d of the transmission layer 22 is between 2μm and 450μm. For example, the width d of the transmission layer can be 2μm, 5μm, 40μm, 100μm, 200μm, 300μm, 400μm, or 450μm, etc. Of course, the width d of the transmission layer 22 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0110] In this embodiment, when the width d of the transmission layer 22 is between 2μm and 450μm, the width of the transmission layer 22 is moderate, which can reduce the shading area of ​​the battery body 1, improve the conversion efficiency of the photovoltaic cell 100, and reduce the requirements for screen printing plate, paste and process control, thereby reducing manufacturing costs.

[0111] In some embodiments, such as Figure 13 As shown, the width d of the transmission layer 22 can be between 5μm and 40μm. For example, the width d of the transmission layer 22 can be 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, or 40μm, etc. Of course, the width d of the transmission layer 22 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0112] In this embodiment, when the width d of the transmission layer 22 is between 5μm and 40μm, it can ensure a reliable connection between the transmission layer 22 and the seed layer 21, and at the same time have better current collection capability, it further reduces shading loss and improves the conversion efficiency of the photovoltaic cell 100.

[0113] In one specific embodiment, such as Figure 12 and Figure 13As shown, the width difference between the transport layer 22 and the seed layer 21 is between 0 and 50 μm. For example, the width difference between the transport layer 22 and the seed layer 21 can be 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 35 μm, or 40 μm, etc. Of course, the width difference between the transport layer 22 and the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0114] In this embodiment, when the width difference between the transmission layer 22 and the seed layer 21 is between 0 and 50 μm, the light shading loss can be reduced, ensuring that the transmission layer 22 and the seed layer 21 have sufficient contact area. This allows for efficient and sufficient current collection while reducing the requirements for printing process precision, lowering manufacturing difficulty, and improving manufacturing yield.

[0115] In some embodiments, such as Figure 12 and Figure 13 As shown, the width difference between the transmission layer 22 and the seed layer 21 can be between 0 and 10 μm. For example, the width difference between the transmission layer 22 and the seed layer 21 can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, etc. Of course, the width difference between the transmission layer 22 and the seed layer 21 can also be other values ​​within the above range. The specific value can be set according to actual needs and is not limited here.

[0116] In this embodiment, when the width difference between the transmission layer 22 and the seed layer 21 is between 0 and 10 μm, it can ensure that the transmission layer 22 and the seed layer 21 have sufficient contact area, improve the fill factor, and improve the conversion efficiency of the photovoltaic cell 100.

[0117] The shapes of the seed layer 21 and the transmission layer 22 can be set to be the same as those of the seed layer 21 and the transmission layer 22 of the photovoltaic cell 100, and have the same technical effect, which will not be described in detail here.

[0118] This application also provides a photovoltaic module, such as Figure 14 As shown, the photovoltaic module includes a cell string 110, an encapsulation layer 120, and a cover plate 130. The cell string 110 is formed by connecting multiple photovoltaic cells 100 as described in any of the embodiments, and / or, the cell string 110 is formed by connecting multiple cell segments 10 as described in any of the embodiments. The encapsulation layer 120 is used to cover the surface of the cell string 110, and the cover plate 130 is used to cover the surface of the encapsulation layer 120 away from the cell string 110. Since the photovoltaic cell 100 has the above-mentioned technical effects, the photovoltaic module including the photovoltaic cell 100 should also have the above-mentioned technical effects, which will not be described in detail here.

[0119] Among them, such as Figure 14As shown, photovoltaic cells 100 are electrically connected in a single piece or in multiple segments to form multiple cell strings 110, and / or cell segments 10 are electrically connected to form multiple cell strings 110. The multiple cell strings 110 are electrically connected in series and / or parallel. Specifically, the multiple cell strings 110 can be electrically connected to each other via conductive links. An encapsulation layer 120 covers the front and back of the solar cell. Specifically, the encapsulation layer 120 can be an organic encapsulation film such as ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene copolymer elastomer (POE) film, polyethylene terephthalate (PET) film, or polyvinyl butyral (PVB). A cover plate 130 can be a light-transmitting cover plate 130 such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 130 facing the encapsulation layer 120 can be an uneven surface to increase the utilization rate of incident light.

[0120] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the device embodiments and terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

[0121] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photovoltaic cell, characterized in that, include: A battery body, the battery body comprising an edge region and a central region arranged from the edge toward the center; Multiple grid lines extend along a first direction of the battery body; along a second direction of the battery body, the multiple grid lines are arranged at intervals on the battery body; each grid line includes a seed layer, which is electrically connected to the battery body. The width of the seed layer in the edge region is greater than the width of the seed layer in the center region; Wherein, the width of the seed layer is the dimension of the seed layer in the second direction.

2. The photovoltaic cell according to claim 1, characterized in that, The edge region includes a first region and a second region, wherein the second region is disposed between the first region and the central region; The width of the seed layer in the first region is greater than the width of the seed layer in the second region.

3. The photovoltaic cell according to claim 1, characterized in that, The width of the seed layer is between 5 μm and 500 μm.

4. The photovoltaic cell according to claim 1, characterized in that, The shape of the seed layer includes one or more of the following: continuous linear, discontinuous linear, and lattice-like.

5. The photovoltaic cell according to claim 4, characterized in that, The lattice-shaped seed layer includes multiple conductive units, the conductive units being one or more of the following shapes: circular, elliptical, rectangular, or trapezoidal.

6. The photovoltaic cell according to any one of claims 1 to 5, characterized in that, Along a second direction of the battery body, the edge regions are located on opposite sides of the central region.

7. The photovoltaic cell according to any one of claims 1 to 5, characterized in that, The edge region surrounds the outer perimeter of the central region.

8. The photovoltaic cell according to any one of claims 1 to 5, characterized in that, Along the second direction of the battery body, the width of the edge region is a, the total length of the photovoltaic cell is b, and 0 < a / b < 2 / 5.

9. The photovoltaic cell according to any one of claims 1 to 5, characterized in that, The grid line also includes a transmission layer, which is disposed on the side of the seed layer opposite to the battery body, and the width of the transmission layer is smaller than the width of the seed layer.

10. The photovoltaic cell according to claim 9, characterized in that, The width of the transmission layer in the edge region is greater than the width of the transmission layer in the center region.

11. The photovoltaic cell according to claim 9, characterized in that, The width of the transport layer is between 2μm and 450μm.

12. The photovoltaic cell according to claim 9, characterized in that, The width difference between the transport layer and the seed layer is between 0 and 50 μm.

13. A battery segmentation method, characterized in that, include: The battery body includes a first side and a second side disposed opposite to each other along a second direction of the battery body; Multiple grid lines extend along a first direction of the battery body; along a second direction of the battery body, the multiple grid lines are arranged at intervals on the battery body; each grid line includes a seed layer, which is electrically connected to the battery body. The width of the seed layer on the second side is greater than at least a portion of the width of the seed layer on the first side; Wherein, the width of the seed layer is the dimension of the seed layer in the second direction.

14. The battery segmentation according to claim 13, characterized in that, Along a first direction of the battery body, the battery body further includes a third side and a fourth side disposed opposite to each other, wherein the width of the seed layer disposed at least partially between the third side and the fourth side is smaller than the width of the seed layer on the third side and / or the fourth side.

15. The battery segmentation according to claim 13 or 14, characterized in that, The width of the seed layer is between 5 μm and 500 μm.

16. The battery segmentation according to claim 13 or 14, characterized in that, The grid line also includes a transmission layer, which is disposed on the side of the seed layer opposite to the battery body, and the width of the transmission layer is smaller than the width of the seed layer.

17. The battery segmentation according to claim 16, characterized in that, The width of the transmission layer on the second side is greater than at least a portion of the width of the transmission layer on the first side.

18. The battery segmentation according to claim 16, characterized in that, The width of the transport layer is between 2μm and 450μm.

19. The battery segmentation according to claim 16, characterized in that, The width difference between the transport layer and the seed layer is between 0 and 50 μm.

20. A photovoltaic module, characterized in that, include: A battery string, wherein the battery string is formed by connecting a plurality of photovoltaic cells as described in any one of claims 1 to 12; and / or, the battery string is formed by connecting a plurality of battery segments as described in any one of claims 13 to 19; Encapsulation layer, the encapsulation layer being used to cover the surface of the battery string; A cover plate for covering the surface of the encapsulation layer away from the battery string.

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