Solar cell and photovoltaic module

Abstract

The application relates to a solar cell and a photovoltaic module. The solar cell comprises a cell body, a first surface and a second surface arranged oppositely, the first surface comprises a center region and an edge region connected with the center region, a first main grid structure is arranged on the first surface, the first main grid structure comprises at least one first main grid and a plurality of second main grids arranged along a first direction, the first main grid is arranged in the edge region, and the second main grid is arranged in the center region; the first direction is perpendicular to the thickness direction of the cell body; wherein, a hollow part is arranged on the first main grid, and a reinforcing grid is arranged in the hollow part; part of the structure of the reinforcing grid is inserted into the cell body, and the distance between the reinforcing grid and the second surface is smaller than the distance between the first main grid and the second surface. The application can improve the problem of blackening of the cell edge.

Description

Technical Field

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

[0002] Solar power generation, due to its cleanliness, safety, convenience, and high efficiency, has become an industry of widespread attention and key development worldwide. With continuous technological innovation, the conversion efficiency of solar cells is also increasing dramatically, making cost reduction and efficiency improvement a top priority for solar energy companies.

[0003] In related technologies, the main grid and fine grids are formed using a step-by-step printing process. The fine grids use a burn-through type paste, while the main grids use a non-burn-through type paste. In the edge region, the contact of the main grid is relatively poor, resulting in blackening of the edge region. Utility Model Content

[0004] Therefore, it is necessary to provide a solar cell and photovoltaic module to address the above problems.

[0005] In a first aspect, this application provides a solar cell, comprising:

[0006] The battery body includes a first surface and a second surface disposed opposite to each other; the first surface includes a central region and an edge region connected to the central region.

[0007] A first main grid structure is disposed on the first surface; the first main grid structure includes at least one first main grid and a plurality of second main grids arranged along a first direction, the first main grid being located in the edge region, and the second main grids being located in the center region; the first direction is perpendicular to the thickness direction of the battery body;

[0008] The first main grid has a hollowed-out portion, and a reinforcing grid is provided inside the hollowed-out portion; part of the reinforcing grid is inserted into the battery body, and the distance between the reinforcing grid and the second surface is less than the distance between the first main grid and the second surface.

[0009] In one embodiment, the reinforcing gate is spaced apart from the first main gate.

[0010] In one embodiment, the reinforcing gate is connected to the first main gate.

[0011] In one embodiment, the orthographic projection edge of the reinforcing grid on the battery body includes a first edge and a second edge, wherein the first edge overlaps with the orthographic projection of the first main grid on the battery body, and the second edge does not overlap with the orthographic projection of the first main grid on the battery body.

[0012] In one embodiment, the length of the first edge is less than the length of the second edge.

[0013] In one embodiment, the first main gate includes:

[0014] Multiple first pads are arranged at intervals along a second direction; the second direction is perpendicular to the thickness direction of the battery body and intersects with the first direction.

[0015] The first gate line is connected to the plurality of first pads;

[0016] The hollow portion includes a first hollow portion disposed on the first grid line, and the reinforcing grid includes a first reinforcing grid disposed within the first hollow portion.

[0017] In one embodiment, the first gate line includes:

[0018] A first connecting line extends along the second direction; the plurality of first pads are disposed on one side of the first connecting line along the first direction;

[0019] Multiple second connection lines are arranged at intervals along the second direction; each second connection line connects the first connection line and the corresponding first pad.

[0020] In one embodiment, the first connecting line is provided with the first hollow portion.

[0021] In one embodiment, the second connecting line is provided with the first hollow portion.

[0022] In one embodiment, the second connecting line is provided with a plurality of the first hollow portions arranged at intervals along the first direction;

[0023] The dimension of the first hollow portion along the first direction is greater than the dimension of the first hollow portion along the second direction; in the first reinforcing grid corresponding to the first hollow portion, the dimension of the first reinforcing grid along the first direction is greater than the dimension of the first hollow portion along the second direction.

[0024] In one embodiment, both ends of the first reinforcing grid along the first direction are connected to the first main grid; both sides of the first reinforcing grid along the second direction are spaced apart from the second connecting line.

[0025] In one embodiment, the cutout portion includes a second cutout portion disposed on the first pad, and the reinforcing gate includes a second reinforcing gate disposed within the second cutout portion.

[0026] In one embodiment, the first pad has a first welding area, and the second cutout portion is disposed around the first welding area.

[0027] In one embodiment, the solar cell further includes a plurality of first fine grids disposed on the first surface, the plurality of first fine grids being arranged at intervals along a second direction and located in the central region and the edge region; the first main grid and the second main grid are both connected to the first fine grids;

[0028] The reinforcing grid is made of the same material as the first fine grid; the second direction is perpendicular to the thickness direction of the battery body and intersects with the first direction.

[0029] In one embodiment, the solar cell further includes:

[0030] Multiple second fine gates are disposed on the first surface and arranged at intervals along the second direction; the characteristics of the second fine gates are opposite to those of the first fine gates.

[0031] A second main gate structure is disposed on the first surface; the second main gate structure includes a plurality of third main gates arranged along the first direction; the third main gates are connected to the second fine gate.

[0032] In one embodiment, the second main gate includes:

[0033] Multiple second pads are arranged at intervals along the second direction;

[0034] The second gate line is connected to the plurality of second pads;

[0035] The second pad has a second welding area and a cutout area, with the cutout area located around the second welding area. A third reinforcing grid is located within the cutout area. A portion of the third reinforcing grid is inserted into the battery body, and the distance between the third reinforcing grid and the second surface is less than the distance between the second pad and the second surface.

[0036] Secondly, this application provides a photovoltaic module, including the solar cell in any embodiment of the first aspect.

[0037] The aforementioned solar cells and photovoltaic modules feature a first main grid in the edge region, with a cutout portion on the first main grid and a reinforcing grid within the cutout portion. A portion of the reinforcing grid is inserted into the cell body, and the distance between the reinforcing grid and the second surface is less than the distance between the first main grid and the second surface; in other words, the reinforcing grid is inserted deeper. This has several advantages: firstly, the reinforcing grid helps improve the ohmic contact in the edge region, collecting charge carriers and thus mitigating the EL blackening problem in the edge region; secondly, the cutout portion accommodating the reinforcing grid does not affect the original arrangement of the first main grid; and thirdly, the cutout portion and the reinforcing grid can serve an alignment function, facilitating rapid assessment of the alignment of the metallization printing and the patterns on the cell body. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a top view schematic diagram of a solar cell provided in an embodiment of this application.

[0040] Figure 2 for Figure 1 A schematic diagram of section AA in the diagram.

[0041] Figure 3 for Figure 1 A partial schematic diagram of the first main grid of the solar cell shown.

[0042] Figure 4 for Figure 1 The diagram shows a cross-sectional view of the reinforcing grid and the first main grid of the solar cell.

[0043] Figure 5 for Figure 1 Another partial schematic diagram of the first main grid of the solar cell shown.

[0044] Figure 6 for Figure 1 Another partial schematic diagram of the first main grid of the solar cell shown.

[0045] Figure 7 for Figure 1 Another partial schematic diagram of the first main grid of the solar cell shown.

[0046] Figure 8 for Figure 1 Another partial schematic diagram of the first main grid of the solar cell shown.

[0047] Figure 9 for Figure 1 A partial schematic diagram of the second main grid of the solar cell shown.

[0048] Figure 10 for Figure 1 Another partial schematic diagram of the second main grid of the solar cell shown.

[0049] Figure label:

[0050] 1. Solar cell; 10. Cell body; 10a. First surface; 10a1. Central region; 10a2. Edge region; 10b. Second surface; 20. First main grid structure; 21. First main grid; 21a. Hollowed-out portion; 21a-1. First hollowed-out portion; 21a-2. Second hollowed-out portion; 211. First pad; 211a. First welding area; 212. First grid line; 2121. First connecting line; 2122. Second connecting line; 22. Second main grid; 221. Second pad; 221a. Second welding area; 222. Second grid line; 22a. Hollowed-out area; 30. Reinforcing grid; 30-1. First reinforcing grid; 30-2. Second reinforcing grid; 40. First fine grid; 50. Second fine grid; 60. Second main grid structure; 61. Third main grid; 70. Third reinforcing grid; X. First direction; Y. Second direction. Detailed Implementation

[0051] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0053] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this application, the first element, part, region, layer, doping type, or portion discussed below may be referred to as a second element, part, region, layer, or portion.

[0054] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0055] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0056] Embodiments of the application are described herein with reference to cross-sectional views illustrating ideal embodiments (and intermediate structures), thus allowing for the expectation of variations in the illustrated shapes due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the application should not be limited to the specific shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing techniques. For instance, implantation regions shown as rectangular typically have rounded or curved features at their edges and / or implantation concentration gradients, rather than a binary change from implantation regions to non-implantation regions. Similarly, buried regions formed by implantation can result in some implantation in the region between the buried region and the surface traversed during implantation. Therefore, the regions shown in the figures are substantially schematic, and their shapes do not represent the actual shapes of regions of the device and do not limit the scope of the application.

[0057] In related technologies, the fine grid uses a burn-through slurry (a highly corrosive slurry), while the main grid uses a non-burn-through slurry (a slurry with shallow or almost no corrosion). During EL testing, the area where the main grid is located at the edge exhibited blackening. Further analysis revealed that the cause of the blackening was poor contact with the main grid.

[0058] In view of this, embodiments of this application provide a solar cell and photovoltaic module to improve the problem of edge blackening.

[0059] Firstly, referring to Figure 1 and Figure 2 As shown, this application provides a solar cell 1, which can be a PERT (Passivated Emitter Rear Totally-diffused) cell, a TOPCon (Tunnel Oxide Passivated Contact) cell, an SHJ (Silicon Hetero Junction) cell, a tandem cell, a BC (Back Contact) cell, etc.

[0060] Specifically, the solar cell 1 includes a cell body 10 and a first main grid structure 20. The cell body 10 includes a first surface 10a and a second surface 10b disposed opposite to each other. One of the first surface 10a and the second surface 10b is a light-facing surface, and the other is a backlighting surface. The first surface 10a includes a central region 10a1 and an edge region 10a2 connected to the central region 10a1. Exemplarily, the edge region 10a2 may be disposed around the central region 10a1.

[0061] It is understood that the battery body 10 may include a silicon substrate and dielectric film, doped conductive layer, passivation layer and antireflection layer disposed on the silicon substrate.

[0062] Furthermore, a first main gate structure 20 is disposed on the first surface 10a. The first main gate structure 20 includes at least one first main gate 21 and a plurality of second main gates 22 arranged along a first direction X. In other words, all the first main gates 21 and all the second main gates 22 are arranged sequentially at intervals along the first direction X. The first main gates 21 are located in the edge region 10a2, and the second main gates 22 are located in the center region 10a1. The first direction X is perpendicular to the thickness direction of the battery body 10. It is understood that the first main gates 21 and the second main gates 22 have the same polarity.

[0063] Furthermore, referring to Figure 3 As shown, the first main grille 21 has a perforated portion 21a, and a reinforcing grille 30 is provided inside the perforated portion 21a. Here, the perforated portion 21a refers to the perforated structure. The reinforcing grille 30 refers to the grille structure that enhances contact. (Refer to...) Figure 4 As shown, a portion of the reinforcing gate 30 is inserted into the battery body 10, and the distance between the reinforcing gate 30 and the second surface 10b is less than the distance between the first main gate 21 and the second surface 10b. In other words, the reinforcing gate 30 is inserted deeper than the first main gate 21. In one example, the first main gate 21 is not inserted into the battery body 10. In another example, a portion of the first main gate 21 is inserted into the passivation layer of the battery body 10. It should be noted that the reinforcing gate 30 can form an ohmic contact with the doped conductive layer of the battery body 10.

[0064] This helps to increase the area where the passivation layer in the battery body 10 is opened by the grid 30, forming more contact points and improving the problem of edge blackening.

[0065] It is understandable that the slurry of the reinforcing grid 30 has a different composition than that of the first main grid 21, and the slurry of the reinforcing grid 30 is more corrosive than that of the first main grid 21.

[0066] It should be noted that grid lines are typically formed by printing and sintering a paste. The paste generally includes conductive materials, binder materials, organic carriers, and additives. The conductive material is usually high-purity silver or aluminum powder, used to provide conductivity for the electrodes. The binder material is mainly glass frit, used to form a good bond with the silicon wafer during sintering. The organic carrier includes organic solvents, resins, and additives, used to disperse and mix the conductive and binder phases, giving the paste good printability. Additives are used to improve the rheological properties and sintering performance of the paste.

[0067] Furthermore, the glass frit mainly plays the following roles: (1) bonding the substrate. The glass frit melts during sintering to form a glass phase, which binds the silver powder particles together and forms a strong adhesion to the silicon wafer surface. (2) etching the antireflective film. Some components in the glass frit (such as lead oxide, tellurium oxide, etc.) can etch the passivation layer (such as silicon nitride antireflective film) on the silicon wafer surface during sintering, exposing the silicon wafer and thus achieving direct contact between the silver electrode and the silicon wafer. (3) forming ohmic contact. During sintering, the glass frit undergoes complex physicochemical reactions with the silver powder and silicon wafer to form a low-resistance metal-semiconductor contact. For example, oxides in the glass frit can be reduced to generate elemental substances, which react with silicon to generate eutectic or intermetallic compounds. (4) adjusting sintering performance: The melting point, viscosity and thermal expansion coefficient of the glass frit can adjust the sintering performance of the slurry, so that it forms an ideal electrode structure during sintering.

[0068] Glass frits are typically composed of various metal oxides, with common components including lead oxide (PbO), tellurium oxide (TeO2), bismuth oxide (Bi2O3), and boron oxide (B2O3). In some embodiments, the glass frit may also include other oxides, such as silicon dioxide (SiO2), aluminum oxide (Al2O3), molybdenum oxide (MoO3), and tantalum oxide (Ta2O5), which can further optimize the performance of the glass frit. In glass frit systems, a higher lead oxide content results in deeper longitudinal piercing depths during sintering, which is beneficial for forming more contact points.

[0069] In the aforementioned solar cell 1, a first main grid 21 is provided in the edge region 10a2, and a cutout portion 21a is provided on the first main grid 21, and a reinforcing grid 30 is provided within the cutout portion 21a. Part of the reinforcing grid 30 is inserted into the cell body 10, and the distance between the reinforcing grid 30 and the second surface 10b is less than the distance between the first main grid 21 and the second surface 10b; in other words, the insertion depth of the reinforcing grid 30 is deeper. Thus, on the one hand, the reinforcing grid 30 helps improve the ohmic contact of the edge region 10a2, collecting charge carriers in the edge region 10a2, thereby improving the EL blackening problem in the edge region 10a2; on the other hand, the cutout portion 21a for accommodating the reinforcing grid 30 means that adding the reinforcing grid 30 does not affect the original arrangement of the first main grid 21; furthermore, the cutout portion 21a and the reinforcing grid 30 can serve an alignment function, facilitating rapid assessment of the alignment of the metallized printing and the patterns on the cell body 10.

[0070] In the aforementioned solar cell 1, on the one hand, the reinforcing grid 30 helps improve the ohmic contact of the edge region 10a2 and collects the charge carriers in the edge region 10a2, thereby improving the EL blackening problem in the edge region 10a2; on the other hand, the hollow portion 21a is provided to accommodate the reinforcing grid 30, so that the addition of the reinforcing grid 30 will not affect the original arrangement of the first main grid 21; furthermore, the hollow portion 21a and the reinforcing grid 30 can play an alignment role, which is beneficial for quickly judging the alignment of the metallization printing and the pattern on the cell body 10.

[0071] In one embodiment, the first main gate structure 20 includes a first main gate 21 located on one side of all the second main gates 22 along the first direction X.

[0072] In one embodiment, the first main gate structure 20 includes two first main gates 21, which are located on both sides of all the second main gates 22 along the first direction X.

[0073] In one embodiment, the reinforcing grid 30 is spaced apart from the first main grid 21. In other words, the reinforcing grid 30 and the first main grid 21 are not connected, that is, the reinforcing grid 30 and the first main grid 21 are not electrically connected. In this way, during sintering, the fusion of the two different slurry systems can be avoided, thereby preventing the part of the structure of the first main grid 21 (the structure connected to the reinforcing grid 30) from being sintered too deeply, which would lead to increased composite loss.

[0074] In one embodiment, the reinforcing gate 30 is connected to the first main gate 21. In other words, the reinforcing gate 30 is electrically connected to the first main gate 21. Thus, after the reinforcing gate 30 collects the charge carriers, they can be conducted out through the first main gate 21, which helps to improve battery efficiency.

[0075] In one embodiment, the orthographic projection edge of the reinforcing grid 30 on the battery body 10 includes a first edge and a second edge. The first edge overlaps with the orthographic projection of the first main grid 21 on the battery body 10, while the second edge does not overlap with the orthographic projection of the first main grid 21 on the battery body 10. In other words, the first edge overlaps with the first main grid 21, while the second edge is not connected to the first main grid 21.

[0076] The above configuration is equivalent to having a portion of the edge of the reinforcing gate 30 overlap and connect with the first main gate 21, while the other portion of the edge remains unconnected to the first main gate 21. This allows the carriers collected by the reinforcing gate 30 to be conducted out, increasing the current; and it also prevents excessive sintering of too many structures in the first main gate 21, which could exacerbate recombination losses.

[0077] In one embodiment, the length of the first edge is less than the length of the second edge. If the first edge is a straight line edge, then the length of the straight line edge is the length of the first edge. If the first edge is a polygonal line edge or a curved edge, then the perimeter of the first edge is the length of the first edge. If the second edge is a straight line edge, then the length of the straight line edge is the length of the second edge. If the second edge is a polygonal line edge or a curved edge, then the perimeter of the second edge is the length of the second edge.

[0078] The above settings help to achieve a better balance between conduction carriers and recombination losses, thereby improving battery efficiency.

[0079] In one embodiment, the first main gate 21 includes a first gate line 212 and a plurality of first pads 211, the plurality of first pads 211 being arranged at intervals along a second direction Y; the second direction Y is perpendicular to the thickness direction of the battery body 10 and intersects with the first direction X. The first gate line 212 is connected to the plurality of first pads 211. The cutout portion 21a includes a first cutout portion 21a-1 disposed on the first gate line 212, and the reinforcing gate 30 includes a first reinforcing gate 30-1 disposed within the first cutout portion 21a-1. The above arrangement is beneficial to improving the blackening problem in the area where the first gate line 212 is located.

[0080] In one embodiment, the first gate line 212 includes a first connecting line 2121 and a plurality of second connecting lines 2122. The first connecting line 2121 extends along a second direction Y. A plurality of first pads 211 are disposed on one side of the first connecting line 2121 along a first direction X. The plurality of second connecting lines 2122 are arranged at intervals along the second direction Y. Each second connecting line 2122 connects the first connecting line 2121 and a corresponding first pad 211. In one example, the number of first pads 211 and the number of second connecting lines 2122 are equal, and the second connecting lines 2122 correspond one-to-one with the first pads 211.

[0081] When the solar cell 1 is a back-contact cell, the above arrangement is beneficial to connecting all the first pads 211 on one side of the first pad 211, which helps to avoid the cross-linking of dissimilar grid lines.

[0082] In one embodiment, such as Figure 3 As shown, the first connecting line 2121 has a first hollow portion 21a-1. This feature helps to improve the blackening problem in the area where the first connecting line 2121 is located.

[0083] Optionally, a first hollow portion 21a-1 is provided on the first connecting line 2121, and the first hollow portion 21a-1 extends along the length direction (i.e., the second direction Y) of the first connecting line 2121.

[0084] Optionally, the first connecting line 2121 is provided with a plurality of first hollow portions 21a-1, which are arranged at intervals along the second direction Y.

[0085] In one embodiment, such as Figure 5 As shown, the second connecting line 2122 is provided with a first hollow part 21a-1.

[0086] It should be noted that in the relevant technology, the first connecting line 2121 is a vertical connecting line, and the second connecting line 2122 is a horizontal connecting line. The width of the second connecting line 2122 ranges from 100μm to 600μm. During EL testing, the blackening phenomenon in the area where the second connecting line 2122 is located is quite severe. By providing a first hollow portion 21a-1 on the second connecting line 2122, the blackening phenomenon in the area where the second connecting line 2122 is located can be effectively improved.

[0087] In one embodiment, the second connecting line 2122 is provided with a plurality of first hollow portions 21a-1 arranged at intervals along a first direction X. The size of the first hollow portion 21a-1 along the first direction X is larger than the size of the first hollow portion 21a-1 along the second direction Y. Specifically, the first direction X is the length direction of the first hollow portion 21a-1, and the second direction Y is the width direction of the first hollow portion 21a-1. In the first reinforcing grille 30-1 corresponding to the first hollow portion 21a-1, the size of the first reinforcing grille 30-1 along the first direction X is larger than the size of the first hollow portion 21a-1 along the second direction Y. Specifically, the first direction X is the length direction of the first reinforcing grille 30-1, and the second direction Y is the width direction of the first reinforcing grille 30-1.

[0088] The above arrangement facilitates the arrangement of the plurality of first cutout portions 21a-1 within the elongated second connecting line 2122. Furthermore, the arrangement of multiple first cutout portions 21a-1 is equivalent to setting multiple alignment marks, which further improves alignment accuracy.

[0089] In one embodiment, such as Figure 6 As shown, a first hollow portion 21a-1 is provided on the second connecting line 2122, and the first hollow portion 21a-1 extends along the length direction of the second connecting line 2122.

[0090] In one embodiment, both ends of the first reinforcing gate 30-1 along the first direction X are connected to the first main gate 21. In one example, both ends of the first reinforcing gate 30-1 along the first direction X are connected to the second connecting line 2122. In another example, one end of the first reinforcing gate 30-1 along the first direction X is connected to the first connecting line 2121, and the other end of the first reinforcing gate 30-1 along the first direction X is connected to the first pad 211.

[0091] Furthermore, the first reinforcing grid 30-1 is spaced apart from the second connecting line 2122 on both sides along the second direction Y.

[0092] The above configuration is equivalent to connecting (e.g., overlapping) the short edge of the first reinforcing grid 30-1 with the first main grid 21, while the long edge of the first reinforcing grid 30-1 is not connected with the first main grid 21.

[0093] In this way, on the one hand, the carriers collected by the reinforcing gate 30 can be conducted out, increasing the current; on the other hand, it can avoid the excessive sintering of the first main gate 21 structure, which would lead to increased recombination losses.

[0094] In one embodiment, such as Figure 7 and Figure 8 As shown, the cutout portion 21a includes a second cutout portion 21a-2 disposed on the first pad 211, and the reinforcing gate 30 includes a second reinforcing gate 30-2 disposed within the second cutout portion 21a-2. This configuration helps to improve the blackening problem in the area where the first pad 211 is located.

[0095] In one embodiment, a first welding area 211a is provided on the first pad 211, and a second cutout portion 21a-2 is disposed around the first welding area 211a. In other words, the second cutout portion 21a-2 is disposed around the first welding area 211a. In this way, the second reinforcing gate 30-2 can be prevented from having an adverse effect on welding, thus preventing the welding performance from deteriorating.

[0096] Optionally, such as Figure 7 As shown, the planar shape of the second cutout portion 21a-2 and the second reinforcing gate 30-2 on the first pad 211 can be strip-shaped.

[0097] Optionally, such as Figure 8 As shown, the planar shape of the second cutout portion 21a-2 and the second reinforcing gate 30-2 on the first pad 211 can be dot-shaped (or block-shaped).

[0098] In one embodiment, such as Figure 1 As shown, the solar cell 1 also includes a plurality of first fine grids 40 disposed on the first surface 10a. The plurality of first fine grids 40 are arranged at intervals along the second direction Y and are located in the central region 10a1 and the edge region 10a2. The first main grid 21 and the second main grid 22 are both connected to the first fine grids 40. The reinforcing grid 30 is made of the same material as the first fine grids 40. The second direction Y is perpendicular to the thickness direction of the cell body 10 and intersects with the first direction X.

[0099] By using the same material for the reinforcing grid 30 and the first fine grid 40, the reinforcing grid 30 and the first fine grid 40 can be printed simultaneously in the same printing process, which helps to reduce the number of steps and lower the manufacturing difficulty.

[0100] In one embodiment, at least two of the first pad 211, the first connecting line 2121, and the second connecting line 2122 are provided with cutouts 21a. This can further improve the problem of edge blackening.

[0101] In one embodiment, the solar cell 1 further includes a second main grid structure 60 and a plurality of second fine grids 50. The plurality of second fine grids 50 are disposed on the first surface 10a and arranged at intervals along the second direction Y; the second fine grids 50 have opposite polarities to the first fine grids 40. The second main grid structure 60 is disposed on the first surface 10a; the second main grid structure 60 includes a plurality of third main grids 61 arranged along the first direction X; the third main grids 61 are connected to the second fine grids 50. In this embodiment, the solar cell 1 is a back-contact cell, and the first surface 10a is the backlight surface.

[0102] Optionally, the reinforced gate 30 can make ohmic contact with the doped conductive layer of the P-region of the back contact cell, thereby improving the blackening problem caused by poor contact in the P-region. It is understood that the reinforced gate 30 can also make ohmic contact with the doped conductive layer of the N-region of the back contact cell.

[0103] In one embodiment, such as Figure 1 As shown, the second main gate structure 60 is located in the central region 10a1, and the first main gate structure 20 includes two first main gates 21, which are located on both sides of the central region 10a1 along the first direction X.

[0104] In one embodiment, the third main gate 61 is located in the central region 10a1. The second main gate structure 60 also includes a fourth main gate (not shown in the figure), and the first main gate structure 20 includes a first main gate 21. The first main gate 21 and the fourth main gate are located on both sides of the central region 10a1 along the first direction X. Both the fourth main gate and the first main gate 21 are edge main gates, and the fourth main gate has a similar structure to the first main gate 21, that is, the fourth main gate has a hollow portion 21a, and a reinforcing gate 30 is provided in the hollow portion 21a.

[0105] In one embodiment, such as Figure 9 and Figure 10 As shown, the second main gate 22 includes a second gate line 222 and a plurality of second pads 221. The plurality of second pads 221 are arranged at intervals along the second direction Y, and the second gate line 222 is connected to the plurality of second pads 221. The second pads 221 are provided with a second welding area 221a and a cutout area 22a, with the cutout area 22a located around the second welding area 221a. A third reinforcing gate 70 is provided within the cutout area 22a. A portion of the third reinforcing gate 70 is inserted into the battery body 10, and the distance between the third reinforcing gate 70 and the second surface 10b is less than the distance between the second pads 221 and the second surface 10b. In other words, compared to the second main gate 22, the third reinforcing gate 70 has a deeper insertion depth. Thus, the third reinforcing gate 70 can open more areas of the passivation layer in the battery body 10, forming more contact points, improving the blackening problem in the area where the second pads 221 are located. Furthermore, it can prevent the third reinforcing gate 70 from adversely affecting the welding area, thereby affecting welding performance.

[0106] It is understood that the third main gate 61 may have a similar structure to the second main gate 22, and this will not be described in detail in the embodiments of this application.

[0107] In one embodiment, the pastes for the first fine grid 40, the second fine grid 50, the first reinforcing grid 30-1, the second reinforcing grid 30-2, and the third reinforcing grid 70 are highly corrosive silver pastes. The pastes for the first main grid structure 20 and the second main grid structure 60 are less corrosive silver pastes, copper pastes, or a mixture of silver and copper pastes. Of course, the pastes for the first fine grid 40, the second fine grid 50, the first reinforcing grid 30-1, the second reinforcing grid 30-2, the third reinforcing grid 70, the first main grid structure 20, and the second main grid structure 60 are not limited to these.

[0108] Secondly, embodiments of this application provide a photovoltaic module, including the solar cell in any embodiment of the first aspect.

[0109] For example, the photovoltaic module includes multiple solar cells that can be wired together in series via solder strips, thereby collecting the electrical energy generated by each individual solar cell for subsequent power transmission. Of course, the solar cells can be arranged at intervals or stacked together in a shingled configuration.

[0110] Furthermore, the photovoltaic module also includes an encapsulation layer and a cover plate (not shown). The encapsulation layer covers the surface of the cell string, and the cover plate covers the surface of the encapsulation layer away from the cell string. Solar cells are electrically connected in a single piece or in multiple segments to form multiple cell strings, which are electrically connected in series and / or parallel. Specifically, in some embodiments, multiple cell strings can be electrically connected through conductive links. The encapsulation layer covers the surface of the solar cells. Exemplarily, the encapsulation layer can be an organic encapsulation film such as an ethylene-vinyl acetate copolymer film, a polyethylene octene co-elastomer film, or a polyethylene terephthalate film. The cover plate can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A solar cell, characterized in that, include: The battery body includes a first surface and a second surface disposed opposite to each other; the first surface includes a central region and an edge region connected to the central region. The first main grid structure is located on the first surface; The first main grid structure includes at least one first main grid and a plurality of second main grids arranged along a first direction, wherein the first main grid is located in the edge region and the second main grids are located in the center region; the first direction is perpendicular to the thickness direction of the battery body. The first main grid has a hollowed-out portion, and a reinforcing grid is provided inside the hollowed-out portion; part of the reinforcing grid is inserted into the battery body, and the distance between the reinforcing grid and the second surface is less than the distance between the first main grid and the second surface.

2. The solar cell according to claim 1, characterized in that, The reinforcing grid is spaced apart from the first main grid.

3. The solar cell according to claim 1, characterized in that, The reinforcing grid is connected to the first main grid.

4. The solar cell according to claim 3, characterized in that, The orthographic projection edge of the reinforcing grid on the battery body includes a first edge and a second edge. The first edge overlaps with the orthographic projection of the first main grid on the battery body, and the second edge does not overlap with the orthographic projection of the first main grid on the battery body.

5. The solar cell according to claim 4, characterized in that, The length of the first edge is less than the length of the second edge.

6. The solar cell according to any one of claims 1-5, characterized in that, The first main gate includes: Multiple first pads are arranged at intervals along a second direction; the second direction is perpendicular to the thickness direction of the battery body and intersects with the first direction. The first gate line is connected to the plurality of first pads; The hollow portion includes a first hollow portion disposed on the first grid line, and the reinforcing grid includes a first reinforcing grid disposed within the first hollow portion.

7. The solar cell according to claim 6, characterized in that, The first gate line includes: A first connecting line extends along the second direction; the plurality of first pads are disposed on one side of the first connecting line along the first direction; Multiple second connection lines are arranged at intervals along the second direction; each second connection line connects the first connection line and the corresponding first pad.

8. The solar cell according to claim 7, characterized in that, The first connecting line has the first hollowed-out portion.

9. The solar cell according to claim 7, characterized in that, The second connecting line is provided with the first hollowed-out portion.

10. The solar cell according to claim 9, characterized in that, The second connecting line is provided with a plurality of the first hollow portions arranged at intervals along the first direction; The dimension of the first hollow portion along the first direction is greater than the dimension of the first hollow portion along the second direction; in the first reinforcing grid corresponding to the first hollow portion, the dimension of the first reinforcing grid along the first direction is greater than the dimension of the first hollow portion along the second direction.

11. The solar cell according to claim 10, characterized in that, Both ends of the first reinforcing grid along the first direction are connected to the first main grid; both sides of the first reinforcing grid along the second direction are spaced apart from the second connecting line.

12. The solar cell according to claim 6, characterized in that, The cutout portion includes a second cutout portion disposed on the first pad, and the reinforcing grid includes a second reinforcing grid disposed within the second cutout portion.

13. The solar cell according to claim 12, characterized in that, The first pad has a first welding area, and the second cutout is located around the first welding area.

14. The solar cell according to any one of claims 1-5, characterized in that, The solar cell further includes a plurality of first fine grids disposed on the first surface, the plurality of first fine grids being arranged at intervals along a second direction and located in the central region and the edge region; the first main grid and the second main grid are both connected to the first fine grids; The reinforcing grid is made of the same material as the first fine grid; the second direction is perpendicular to the thickness direction of the battery body and intersects with the first direction.

15. The solar cell according to claim 14, characterized in that, The solar cell also includes: Multiple second fine gates are disposed on the first surface and arranged at intervals along the second direction; the characteristics of the second fine gates are opposite to those of the first fine gates. A second main gate structure is disposed on the first surface; the second main gate structure includes a plurality of third main gates arranged along the first direction; the third main gates are connected to the second fine gate.

16. The solar cell according to any one of claims 1-5, characterized in that, The second main gate includes: Multiple second pads are arranged at intervals along a second direction; the second direction is perpendicular to the thickness direction of the battery body and intersects with the first direction; The second gate line is connected to the plurality of second pads; The second pad has a second welding area and a cutout area, with the cutout area located around the second welding area. A third reinforcing grid is located within the cutout area. A portion of the third reinforcing grid is inserted into the battery body, and the distance between the third reinforcing grid and the second surface is less than the distance between the second pad and the second surface.

17. A photovoltaic module, characterized in that, Including the solar cell as described in any one of claims 1-16.

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