Photovoltaic module

Abstract

The utility model discloses an embodiment related to photovoltaic field provides a kind of photovoltaic module, at least can improve photoelectric conversion efficiency while improving yield rate.Photovoltaic module includes: solar cell, the solar cell includes cutting surface, first surface and second surface, the two sides of cutting surface are respectively connected with first surface and second surface, the solar cell has multiple first edge grid lines in the end close to cutting surface, the multiple first edge grid lines are located first surface and are spaced along first direction arrangement, the interval between adjacent first edge grid line is first interval D1;Passivation film, the passivation film at least covers cutting surface and the first surface of solar cell, the interval that the passivation film at least covers first surface is second interval D2;The first interval D1 with second interval D2 satisfy: 2D1≤D2<5D1.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaics, and in particular to a photovoltaic module. Background Technology

[0002] Currently, with the gradual depletion of fossil fuels, solar cells are becoming increasingly widely used as a new energy alternative. A solar cell is a device that converts sunlight into electrical energy. Solar cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient utilization of electrical energy.

[0003] Current solar cells mainly include IBC cells (Interdigitated Back Contact), TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated emitter and real cell), and heterojunction cells. Different film layer configurations and functional limitations are used to reduce optical losses and decrease photogenerated carrier recombination on and within the silicon substrate, thereby improving the photoelectric conversion efficiency of solar cells.

[0004] In the process of assembling solar cells into strings, the entire cell is typically sliced, and the sliced ​​cells are then assembled into strings. This helps reduce encapsulation losses, optimize process issues in module manufacturing, improve module reliability, and also helps reduce manufacturing costs. However, this technology also brings some new challenges and problems, such as the probability of cell breakage and efficiency losses at the cutting surface, which require further optimization and improvement. Utility Model Content

[0005] This utility model provides a photovoltaic module that at least helps to improve the photoelectric conversion efficiency of solar cells and increase yield.

[0006] According to some embodiments of the present invention, one aspect of the present invention provides a photovoltaic module, including: a battery string, which is composed of multiple solar cells connected together; the solar cells include: a cut surface (11), a first surface and a second surface, the two sides of the cut surface are respectively connected to the first surface and the second surface, the end of the solar cell near the cut surface has multiple first edge grid lines (111), the multiple first edge grid lines (111) are located on the first surface and are spaced apart along a first direction, the spacing between adjacent first edge grid lines (111) is a first spacing D1; a passivation film (120), the passivation film (120) at least covers the cut surface (11) and the first surface of the solar cell, the spacing of the passivation film (120) at least covering the first surface is a second spacing D2; the first spacing D1 and the second spacing D2 satisfy: 2D1≤D2<5D1; an encapsulating film for covering the surface of the battery string; a cover plate for covering the surface of the encapsulating film away from the battery string.

[0007] In some embodiments, the distance between the first edge grid line closest to the cutting surface (11) and the cutting surface (11) is a third spacing D3, and the first spacing D1 and the third spacing D3 satisfy: 0.3D1<D3≤0.8D1.

[0008] In some embodiments, the third spacing D3 ranges from 0.2 mm to 0.8 mm.

[0009] In some embodiments, the first surface further includes a first edge (101); the solar cell further includes: a plurality of intermediate grid lines (113) and a second edge grid line (112), the second edge grid line (112) being close to the first edge, and the intermediate grid lines (113) being located between the second edge grid line (112) and the first edge grid line (111); the spacing between adjacent intermediate grid lines (113) is a fourth spacing D4, and the spacing between adjacent second edge grid lines (112) is a fifth spacing D5; the first spacing D1 and the fourth spacing D4 satisfy: D1 < D4 < 1.5D1; the first spacing D1 and the fifth spacing D5 satisfy: 0.5D1 < D5 ≤ 5D1.

[0010] In some embodiments, the passivation film (120) also covers the second edge gate line (112), and the second spacing D2 and the fifth spacing D5 satisfy: D5<D2≤3D5.

[0011] In some embodiments, the first surface further includes a second edge (102) that connects the first edge (101) and the cut surface (11). The distance between the end of the first gate line and the second edge (102) is a sixth spacing D6. The fourth spacing D4 and the sixth spacing D6 satisfy: 0.3D4 < D6 ≤ 0.8D4. The first gate line is at least one of the first edge gate line (111), the second edge gate line (112), and the middle gate line (113).

[0012] In some embodiments, the first edge (101) and the second edge (102) have chamfers (103); the distance between the end of the second gate line and the chamfer (103) is a seventh spacing D7, the sixth spacing D6 and the fourth spacing D4 satisfy: 0.3D4<D6≤0.8D4; the seventh spacing and the fourth spacing satisfy: 0.4D7<D4≤0.9D7; the second gate line is at least one of the second edge gate line (112) and the middle gate line (113).

[0013] In some embodiments, the distance between the second edge gate line (112) closest to the first edge (101) and the first edge (101) is the eighth spacing D8, and the fourth spacing D4 and the eighth spacing satisfy: 0.3D8<D4≤0.8D8.

[0014] In some embodiments, the sum of the first spacing D1 and the fifth spacing D5 is greater than or equal to 0.6 times the fourth spacing D4 and less than 2 times the fourth spacing D4.

[0015] In some embodiments, the solar cell further includes a first harpoon structure (131) located near the first edge and in contact with N second edge grid lines (112), where 1 ≤ N ≤ 5.

[0016] In some embodiments, the second edge grid line (112) includes a first sub-grid line and a second sub-grid line. The first sub-grid line is close to the first edge and is divided into a first broken grid and a second broken grid arranged along the second direction by two harpoons of the first harpoon structure. The number of the first sub-grid lines is 1 to 3.

[0017] In some embodiments, the solar cell further includes a second harpoon structure, which is close to the cut surface and contacts M first edge grid lines (111), where N < M and 3 ≤ M ≤ 10.

[0018] In some embodiments, the first edge grid line (111) includes a third sub-grid line and a fourth sub-grid line, the fourth sub-grid line being close to the cutting surface, and the third sub-grid line being divided into a third broken grid and a fourth broken grid arranged along the second direction by the two harpoons of the fourth harpoon structure; the number of the third sub-grid lines is 1 to 5.

[0019] In some embodiments, the number of the third sub-grid lines is 1 to 3, and the fourth sub-grid line is divided into a fifth and a sixth broken grid arranged along the second direction by the two harpoons of the second harpoon structure; the number of the fourth sub-grid lines is 1 to 5.

[0020] In some embodiments, the passivation film includes a first portion and a second portion, the first portion being located on the cut surface and the second portion being located on the first surface, wherein the thickness of the first portion is greater than the thickness of the second portion.

[0021] In some embodiments, the angle between the cutting surface and the first surface is one of an obtuse angle and an acute angle; the angle between the cutting surface and the second surface is the other of an obtuse angle and an acute angle.

[0022] The technical solution provided by this utility model embodiment has at least the following advantages:

[0023] In the technical solution provided by this utility model embodiment, a first edge grid line is provided, and multiple first edge grid lines close to the cut surface are arranged at intervals. This can efficiently collect carrier losses caused by mechanical damage near the cut surface, reduce recombination, and improve carrier transport efficiency. A passivation film is provided, and the first spacing D1 and the second spacing D2 satisfy: 2D1≤D2<5D1, that is, the passivation film covers at least the edge passivation film and two or more edge grid lines. The passivation film can act as a mechanical buffer layer, reducing the risk of microcrack propagation, thereby improving the yield of the battery. The passivation film covering the first edge grid line of the cut surface can avoid the problem of edge grid lines being unwelded, thus preventing the risk of edge breakage and grid breakage of the battery cell. Attached Figure Description

[0024] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1This is a schematic diagram of a solar cell provided in an embodiment of the present invention;

[0026] Figure 2 A first partial view of a solar cell provided in an embodiment of the present invention;

[0027] Figure 3 A second partial view of a solar cell provided in an embodiment of the present invention;

[0028] Figure 4 A third partial view of a solar cell provided in an embodiment of the present invention;

[0029] Figure 5 A fourth partial view of a solar cell provided in an embodiment of the present invention;

[0030] Figure 6 A fifth partial view of a solar cell provided in an embodiment of the present invention;

[0031] Figure 7 A sixth partial view of a solar cell provided in an embodiment of the present invention;

[0032] Figure 8 A seventh partial view of a solar cell provided in an embodiment of the present invention;

[0033] Figure 9 A schematic diagram of a stacked battery provided for another embodiment of the present invention;

[0034] Figure 10 This is a schematic diagram of a photovoltaic module provided in another embodiment of the present invention. Detailed Implementation

[0035] As can be seen from the background technology, the yield and photoelectric conversion efficiency of current photovoltaic modules are not good.

[0036] This utility model provides a photovoltaic module that, by setting a first edge grid line and a passivation film to cover the cut surface and the first edge grid line, shortens the distance between the first edge grid line and the cut surface, and uses the passivation film to improve the passivation effect and reduce the probability of breakage, thereby increasing the yield and photoelectric conversion efficiency of the solar cell.

[0037] In the description of the embodiments of this utility model, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this utility model, "multiple" means two or more, unless otherwise explicitly defined.

[0038] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] In the description of this utility model embodiment, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0040] In the description of the embodiments of this utility model, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0041] In the description of the embodiments of this utility model, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0042] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0043] In the accompanying drawings corresponding to the embodiments of this utility model, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0044] In the description of the embodiments of this utility model, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or it can have another component present in between. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located in between.

[0045] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0046] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this utility model to facilitate a better understanding of the invention. However, the technical solutions claimed by this utility model can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0047] According to some embodiments of the present invention, one aspect of the present invention provides a solar cell for improving photoelectric conversion efficiency and yield.

[0048] Figure 1 This is a schematic diagram of a solar cell provided in an embodiment of the present invention.

[0049] refer to Figure 1A solar cell includes: a cut surface 11, a first surface, and a second surface. The two sides of the cut surface 11 are connected to the first surface and the second surface, respectively. The end of the solar cell near the cut surface 11 has multiple first edge grid lines 111. The multiple first edge grid lines 111 are located on the first surface and are spaced apart along a first direction. The spacing between adjacent first edge grid lines 111 is a first spacing D1. A passivation film 120 covers at least the cut surface 11 and the first surface of the solar cell. The spacing between the passivation film 120 covering at least the first surface is a second spacing D2. The first spacing D1 and the second spacing D2 satisfy: 2D1≤D2<5D1.

[0050] In the technical solution provided by this embodiment of the utility model, a first edge grid line 111 is provided, and multiple first edge grid lines 111 close to the cut surface 11 are arranged at intervals. This can efficiently collect carrier losses caused by mechanical damage near the cut surface, reduce recombination, and improve carrier transport efficiency. A passivation film 120 is provided, and the first spacing D1 and the second spacing D2 satisfy: 2D1≤D2<5D1, that is, the passivation film 120 covers at least the edge passivation film and two or more first edge grid lines 111. The passivation film 120 can act as a mechanical buffer layer, reducing the risk of microcrack propagation, thereby improving the yield of the battery. The passivation film 120 covering the first edge grid lines 111 of the cut surface 11 can avoid the problem of edge grid lines being unwelded, thus preventing the risk of edge breakage and grid breakage of the battery cell.

[0051] The solar cells provided in the above embodiments and their effects will be described in detail below with reference to the accompanying drawings.

[0052] In some embodiments, the entire solar cell can be any one of IBC, TOPCON, PERC, and heterojunction cells. The solar cell can also be a sliced ​​cell. Correspondingly, a cell that has been sliced ​​from a single cell is called a sliced ​​cell, and a sliced ​​cell can be any one of IBC, TOPCON, PERC, and heterojunction cells.

[0053] A sliced ​​battery refers to a battery cell that has been cut into two or more slices using a cutting technique. The current of each sliced ​​battery is 1 / n of the current of the original whole battery cell, where n is the number of sliced ​​batteries formed from the whole cell. Depending on the value of n, sliced ​​batteries can include any number of sliced ​​batteries, such as two-slice, three-slice, four-slice, and eight-slice batteries. For example... Figure 1 The two-slice battery shown.

[0054] It should be noted that the number of facets in a sliced ​​battery can vary depending on where it is cut. For example, Figure 1The sliced ​​battery shown includes one cut surface; the three-slice battery may include two cut surfaces; the nine-slice battery may include two cut surfaces, three cut surfaces, or four cut surfaces.

[0055] The sliced ​​battery can be segmented by means of a direction parallel to or perpendicular to the extension direction of the grid lines. This utility model embodiment uses... Figure 1 The segmentation process is performed parallel to the extension direction of the gate line as an example.

[0056] In some embodiments, the front side of a solar cell refers to the light-receiving surface, and the back side refers to the light-receiving surface. The back side can also receive incident light, but its efficiency in receiving incident light is lower than that of the light-receiving surface. The first surface is either the front or the back side, and the second surface is the other of the front or the back side.

[0057] In some embodiments, the angle between the first surface and the cut surface can be any value, meaning the cut surface and the thickness direction of the entire solar cell can be intersecting or parallel to any value. It is only necessary to ensure breakage between two adjacent cell slices.

[0058] In some embodiments, the angle between the cut surface 11 and the first surface is one of an obtuse angle and an acute angle; the angle between the cut surface 11 and the second surface is the other of an obtuse angle and an acute angle. Thus, when the entire solar cell is obliquely cut to form a sliced ​​cell, the cross-section of the sliced ​​cell can be considered as an oblique surface with respect to the first and second surfaces of the sliced ​​cell. Based on this, compared to dividing the entire solar cell along its thickness direction to form the cross-section of the sliced ​​cell, the inclined cross-section designed in one embodiment of the present invention has a lower atomic arrangement density and a lower covalent bond density. Therefore, the connection between adjacent atoms on the cross-section is weaker, which is more conducive to the passivation film 120 on the cross-section forming bonds with the dangling bonds on the cross-section. That is, it makes it easier for the passivation film 120 to saturate the dangling bonds on the cross-section. Furthermore, the passivation film 120 can also passivate other surface defects on the cross-section, which is beneficial to further enhance the ability of the passivation film 120 to reduce the defect state density of the cross-section, thereby further reducing the recombination centers on the cross-section and lowering the carrier recombination probability.

[0059] The substrate of the entire solar cell is crystalline silicon, which has a face-centered cubic (FCC) crystal structure. Due to the microscopic anisotropy of crystalline silicon, the distribution of atoms on different crystal planes is different. Among them, the (111) crystal plane has the lowest silicon atom density in monocrystalline silicon, while the (110) crystal plane has the highest atom density. In this embodiment of the invention, a sliced ​​cell is formed by oblique cutting, that is, more (111) planes are formed on the oblique cross-section designed on the sliced ​​cell, so that the cross-section has fewer dangling bonds, and thus the passivation film 120 can passivate the cross-section better.

[0060] refer to Figure 5 The angle θ between the cut surface 11 and the first surface is an acute angle, which can be between 45° and 80°. If the acute angle is less than 45°, the inclination of the cut surface 11 relative to the first surface is too large. In this case, the portion of the sliced ​​battery including the cut surface can be considered as a tip protruding from the entire sliced ​​battery. The smaller the acute angle, the more protruding the tip, and the easier it is for the tip to break under pressure, which is not conducive to improving the structural stability of the sliced ​​battery. If the acute angle is greater than 80°, the inclination of the cut surface 11 relative to the first surface is too small, which is not conducive to reducing the atomic arrangement density on the cut surface 11, and therefore not conducive to improving the passivation effect of the passivation film 120 on the cut surface. Therefore, designing the acute angle to be between 45° and 80° and controlling the inclination of the cut surface relative to the first surface is beneficial to improving the structural stability of the sliced ​​battery, reducing the probability of sliced ​​battery breakage, and effectively reducing the atomic arrangement density on the cut surface, so as to improve the passivation effect of the passivation film 120 on the cut surface.

[0061] In some embodiments, the first surface further includes a first edge 101 and a second edge 102, the second edge 102 connecting the first edge 101 and the cut surface 11.

[0062] In some embodiments, the first edge 101 and the second edge 102 have a chamfer 103. The chamfer 103 is cut from a silicon ingot to make full use of the silicon ingot; secondly, it is to reduce the risk of the silicon wafer or cell breaking under external stress due to cracks at the edge of the silicon wafer.

[0063] The first edge grid line 111, the second edge grid line 112 (described later), and the middle grid line 113 are sub-grid lines of the battery cell, used to collect current and transmit it to the connecting components.

[0064] The first edge grid line 111 refers to the grid line near the cutting surface 11. The spacing of this part of the grid line is different from the spacing of the middle grid line. It is artificially defined as the first edge grid line. The subsequent second edge grid line is similar. The second edge grid line is close to the first edge. The spacing of the second edge grid line is different from the spacing of the middle grid line. It is artificially defined as the second edge grid line.

[0065] It should be noted that there is no standard value for the number of the first edge grid line 111 and the second edge grid line 112. The range is 2 to 10. Those skilled in the art can set the number of the first edge grid line and the second edge grid line according to their needs.

[0066] In some embodiments, the spacing between adjacent first edge grid lines 111 is a first spacing D1. The distance between the first edge grid line closest to the cutting surface 11 and the cutting surface 11 is a third spacing D3, and the spacing between the end of the first edge grid line 111 and the second edge 102 is also a sixth spacing D6.

[0067] In some embodiments, the first spacing D1 and the third spacing D3 satisfy the condition: 0.3D1 < D3 ≤ 0.8D1. For example, the third spacing D3 is 0.35D1, 0.4D1, 0.5D1, 0.6D1, 0.7D1, or 0.8D1. The third spacing is smaller than the first spacing, so that the first edge gate line 111 is set as close as possible to the cutting surface 11, reducing the area not covered by the edge gate line, increasing the carrier collection area, and thus improving the photoelectric conversion efficiency.

[0068] In some embodiments, the third spacing D3 is equal to the sixth spacing D6, so that when the connecting component is welded to the first edge grid line, there is a sufficient area for operation, reducing the difficulty of the process. The sixth spacing is larger, which can also avoid the risk of cracking during welding.

[0069] In some embodiments, the third spacing D3 ranges from 0.2 mm to 0.8 mm. The range of the third spacing D3 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm.

[0070] In some embodiments, the sliced ​​battery further includes: a plurality of intermediate grid lines 113 and a second edge grid line 112, the second edge grid line 112 being close to the first edge 101, and the intermediate grid lines 113 being located between the second edge grid line 112 and the first edge grid line 111.

[0071] In some embodiments, the spacing between adjacent second edge grid lines 112 is a fifth spacing D5, the distance between the end of the second edge grid line 112 and the chamfer 103 is a seventh spacing D7, the distance between the second edge grid line 112 closest to the first edge 101 and the first edge 101 is an eighth spacing D8, and the spacing between the end of the second edge grid line 112 and the second edge 102 is also a sixth spacing.

[0072] In some embodiments, the first spacing D1 and the fifth spacing D5 satisfy the condition: 0.5D1 < D5 ≤ 5D1. For example, the fifth spacing D5 is 0.55D1, 0.6D1, 1D1, 2D1, 3D1, or 5D1. When the first spacing D1 and the fifth spacing D5 are within the above range, corresponding to the cutting area, the overall length of the solar cell can be shortened and the carrier collection area can be increased.

[0073] In some embodiments, the fifth spacing D5 and the fourth spacing D4 satisfy the condition: 0.3D4 < D5 ≤ D4. For example, the fifth spacing D5 is 0.33D4, 0.4D4, 0.5D4, 0.8D4, 0.9D4, or D4. This avoids the problem of poor soldering between the solar cells and the second edge grid lines, thus improving the yield of photovoltaic modules.

[0074] In some embodiments, the fifth spacing D5 and the eighth spacing D8 satisfy the condition: 0.3D5 < D8 ≤ 0.8D5. For example, the eighth spacing D8 is 0.33D5, 0.4D5, 0.5D5, 0.6D5, 0.7D5, or 0.8D5. This reduces the distance between the second edge grid lines, increases the carrier collection area of ​​the solar cell, and the passivation film can passivate part of the second edge grid lines and the surface of the solar cell, improving passivation performance.

[0075] In some embodiments, the fifth spacing D5 and the sixth spacing D6 satisfy the condition: 0.3D6 < D5 ≤ 1.2D6. For example, the fifth spacing D5 is 0.33D6, 0.4D6, 0.6D6, 0.8D6, D6, or 1.2D6.

[0076] In some embodiments, the fifth spacing D5 and the seventh spacing D7 satisfy the condition: 0.8D5 < D7 ≤ D5. For example, the seventh spacing D7 is 0.8D5, 0.84D5, 0.88D5, 0.91D5, 0.97D5, or D5. Thus, the seventh spacing D7 is less than or equal to the fifth spacing D5, corresponding to a larger distance between the grid line at the chamfer and the edge of the solar cell, which can ensure the chamfering accuracy of the silicon wafer processing and avoid damage problems caused by the chamfer.

[0077] In some embodiments, the spacing between adjacent intermediate gate lines 113 is a fourth spacing D4, the distance between the end of the intermediate gate line 113 and the chamfer 103 is a seventh spacing D7, and the spacing between the end of the intermediate gate line 113 and the second edge 102 is also a sixth spacing.

[0078] In some embodiments, the first spacing D1 and the fourth spacing D4 satisfy the condition: D1 < D4 < 1.5D1. For example, the fourth spacing D4 is 1.1D1, 1.2D1, 1.3D1, 1.4D1, or 1.49D1. In this way, the distance between the first edge grid lines near the edge of the solar cell is smaller, which can collect more current and also avoid the problem of poor soldering.

[0079] In some embodiments, the fourth spacing D4 and the sixth spacing D6 satisfy the condition: 0.3D4 < D6 ≤ 0.8D4. For example, the sixth spacing D6 is 0.33D4, 0.4D4, 0.5D4, 0.6D4, 0.7D4, or 0.8D4.

[0080] In some embodiments, the fourth spacing D4 and the seventh spacing D7 satisfy the condition: 0.4D7 < D4 ≤ 0.9D7. For example, the fourth spacing D4 is 0.43D7, 0.46D7, 0.5D7, 0.6D7, 0.7D7, or 0.9D7.

[0081] In some embodiments, the fourth spacing D4 and the eighth spacing D8 satisfy the condition: 0.3D8 < D4 ≤ 0.8D8. For example, the fourth spacing D4 is 0.33D8, 0.46D8, 0.5D8, 0.6D8, 0.7D8, or 0.8D8.

[0082] In some embodiments, the eighth spacing D8 and the sixth spacing D6 satisfy: 1D6≤D8≤1.2D6. For example, the eighth spacing D8 is D6, 1.03D6, 1.06D6, 1.1D6, 1.16D6, or 1.2D6.

[0083] In some embodiments, the eighth spacing D8 and the seventh spacing D7 satisfy: 1D8≤D7<2D8. For example, the seventh spacing D7 is D8, 1.46D8, 1.5D8, 1.6D8, 1.8D8, or 1.9D8.

[0084] In some embodiments, the seventh spacing D7 and the sixth spacing D6 satisfy the condition: 1D6 ≤ D7 < 2D6. For example, the seventh spacing D7 is D6, 1.1D6, 1.3D6, 1.5D6, 1.7D6, or 1.9D6. Thus, the seventh spacing D7 is greater than the sixth spacing D6, corresponding to a larger distance between the grid lines at the chamfer and the edge of the solar cell, which can ensure the chamfering accuracy of the silicon wafer and avoid damage problems caused by the chamfer.

[0085] In some embodiments, the passivation film 120 may be a multilayer structure or a single-layer structure, and may be one or more of alumina, silicon oxide, silicon nitride or silicon oxynitride.

[0086] In some embodiments, a passivation film 120 covers the ends of a portion of the first edge gate line 111, the second edge gate line 112, and a portion of the middle gate line 113.

[0087] In some embodiments, the passivation film 120 includes a first portion and a second portion, the first portion being located on the cut surface and the second portion being located on the first surface, the thickness of the first portion being greater than the thickness of the second portion.

[0088] The passivation film 120 at least covers the first surface with a spacing of the second spacing D2.

[0089] In some embodiments, the passivation film 120 also covers the second edge gate line 112, and the second spacing D2 and the fifth spacing D5 satisfy: D5 < D2 ≤ 3D5. For example, the second spacing D2 is 1.1D5, 1.4D5, 1.6D5, 2.2D5, 2.7D5 or 3D5.

[0090] In some embodiments, the second spacing D2 and the sixth spacing D6 satisfy the condition: 1.3D6 < D2 ≤ 3D6. For example, the second spacing D2 is 1.4D6, 1.6D6, 2.2D6, 2.5D6, 2.8D6, or 3D6.

[0091] In some embodiments, the second spacing D2 and the seventh spacing D7 satisfy the condition: 1.5D7 < D2 ≤ 4D7. For example, the second spacing D2 is 1.6D7, 1.8D7, 2.2D7, 2.6D7, 3.3D7, or 4D7.

[0092] It should be noted that the sixth spacing D6 mentioned above refers to the distance between the first grid line and the second edge, wherein the first grid line is at least one of the first edge grid line 111, the second edge grid line 112, and the middle grid line 113. The seventh spacing D7 refers to the spacing between the second grid line and the chamfer, wherein the second grid line is at least one of the second edge grid line 112 and the middle grid line 113.

[0093] In some embodiments, the sum of the first spacing D1 and the fifth spacing D5 is greater than or equal to 0.6 times the fourth spacing D4 and less than 2 times the fourth spacing D4, that is, 0.6D4≤D1+D5≤2D4.

[0094] Figure 2 A first partial view of a solar cell provided in an embodiment of the present invention; Figure 3 A second partial view of a solar cell provided in an embodiment of the present invention; Figure 4 A third partial view of a solar cell provided in an embodiment of the present invention; Figure 5 A fourth partial view of a solar cell provided in an embodiment of the present invention; Figure 6 A fifth partial view of a solar cell provided in an embodiment of the present invention; Figure 7 A sixth partial view of a solar cell provided in an embodiment of the present invention; Figure 8 This is a seventh partial view of a solar cell provided in an embodiment of the present invention.

[0095] It should be noted that, Figures 2-5 This is a partial view of the grid pattern on the front. Figure 2 and Figure 3 This is a schematic diagram of the structure near the cut surface. Figure 4 and Figure 5 This is a schematic diagram of the structure near the first edge; Figures 6-8 This is a partial view of the grid line arrangement on the back. Figure 6 and Figure 7 This is a schematic diagram of the structure near the cut surface. Figure 8 This is a schematic diagram of the structure near the first edge. To distinguish between the front and back grid lines, the grid lines on the front are labeled with 2, and the grid lines on the back are labeled with 3.

[0096] In some embodiments, reference Figure 2 The solar cell also includes a second harpoon structure 22, which is located near the cut surface 11 and contacts M first edge grid lines 111, where N < M and 3 ≤ M ≤ 10. The second harpoon structure 22 includes a first harpoon 221 and a second harpoon 222. The second harpoon structure 22 is also electrically connected to a portion of the intermediate grid lines 213.

[0097] In some embodiments, reference Figure 3 The first edge grid line 211 includes a third sub-grid line 241 and a fourth sub-grid line 242. The fourth sub-grid line 242 is close to the cutting surface 11. The third sub-grid line 241 is divided into a third broken grid and a fourth broken grid arranged along the second direction by the two harpoons of the second harpoon structure 22. The number of third sub-grid lines 242 is 1 to 5.

[0098] The third sub-grid line includes a first type of broken grid 2411 and a first segmentation portion 2412. The first type of broken grid 2411 includes a third broken grid and a fourth broken grid. The spacing between adjacent third sub-grid lines 241 is a first length L1, and the spacing between adjacent fourth sub-grid lines 242 is a second length L2. The first length L1 and the second length L2 satisfy: 0.5L1≤L2≤L1.

[0099] In some embodiments, reference Figure 4 The solar cell also includes a first harpoon structure 23, which is located near the first edge and contacts N second edge grid lines 112, where 1 ≤ N ≤ 5. The first harpoon structure 23 includes a third harpoon 231 and a fourth harpoon 232.

[0100] In some embodiments, reference Figure 5The second edge grid line 212 includes a first sub-grid line 251 and a second sub-grid line 252. The first sub-grid line 251 is close to the first edge. The first sub-grid line 251 is divided into a first broken grid and a second broken grid arranged along the second direction by the two harpoons of the first harpoon structure 23. The number of the first sub-grid lines 252 is 1 to 3.

[0101] The first sub-gate line 251 includes a second type of broken gate 2511 and a second segment 2512. The second type of broken gate 2511 includes a first broken gate and a second broken gate.

[0102] In some embodiments, reference Figure 6 The back of the solar cell also includes a second harpoon structure 32, which is close to the cut surface and contacts M first edge grid lines 111, where N < M and 3 ≤ M ≤ 10.

[0103] In some embodiments, reference Figure 7 The first edge grid line includes a third sub-grid line 341 and a fourth sub-grid line 343. The fourth sub-grid line is close to the cutting surface. The third sub-grid line is divided into a third broken grid and a fourth broken grid arranged along the second direction by two harpoons of the fourth harpoon structure. The number of third sub-grid lines is 1 to 3. The first edge grid line also includes a fifth sub-grid line 342.

[0104] Continue to refer to Figure 7 The fourth sub-grid line 343 is divided into a fifth and a sixth broken grid arranged along the second direction by two harpoons of the second harpoon structure; the number of the third sub-grid lines is 1 to 3, and the number of the fourth sub-grid lines is 1 to 5.

[0105] The third sub-grid line includes a third type of broken grid 3411 and a third segment 3412. The third type of broken grid 3411 includes a fifth type of broken grid and a sixth type of broken grid. The fourth sub-grid line includes a fourth type of broken grid 3431 and a fourth segment 3432. The fourth type of broken grid 3431 includes a fifth type of broken grid and a sixth type of broken grid. The spacing between adjacent third sub-grid lines is a third length L3, and the spacing between adjacent fourth sub-grid lines is a fourth length L4. The third length L3 and the fourth length L4 satisfy: 0.3L3≤L4≤0.8L3. In some embodiments, reference... Figure 8 The solar cell also includes a first harpoon structure 33, which is close to the first edge and contacts N second edge grid lines 112, where 1≤N≤5.

[0106] In some embodiments, the front side also includes a first solder joint 20, which serves as a locally thickened area for each grid line to be welded to the connecting component, thereby increasing the welding area and improving the welding effect.

[0107] It should be noted that the solar cell can be a gridless solar cell, that is, the solar cell does not have a main grid, and the connecting parts are welded to the sub-grid.

[0108] In some embodiments, the front side may also include a first connecting line, which is connected to each of the first solder joints. The first connecting line can improve the connectivity and penetration between the grid lines, thereby improving battery efficiency and reducing the shading area.

[0109] In some embodiments, the back side also includes a second solder joint 30, which serves as a locally thickened area for each grid line and is used to weld with the connecting component, thereby increasing the welding area and improving the welding effect.

[0110] In some embodiments, the back side may also include a second connecting line, which is connected to each of the second solder joints. The second connecting line can improve the connectivity and penetration between the grid lines, thereby improving battery efficiency and reducing the shading area.

[0111] Accordingly, another embodiment of this utility model provides a tandem battery, including the solar cell provided in the above embodiment, and the same or corresponding technical features as those in the above embodiment will not be described in detail here.

[0112] Figure 9 This is a schematic diagram of a stacked battery according to another embodiment of the present invention.

[0113] refer to Figure 9 The tandem solar cell includes: a bottom cell, which is a solar cell as described in any of the above embodiments; and a top cell, which is located on top of the bottom cell.

[0114] In some embodiments, the stacked battery has a first grid line 366 of a first polarity and a second grid line 367 of a second polarity, the first grid line 366 being electrically contacted with the top battery 360 and the second grid line 367 being electrically contacted with the bottom battery 350.

[0115] In some embodiments, an interface layer 361 is provided between the top battery and the bottom battery.

[0116] It is worth noting that the stacked battery in this embodiment only shows two layers of solar cells. Those skilled in the art can set up three layers of solar cells or more than three layers of multi-layer stacked solar cells according to actual needs.

[0117] In some embodiments, the top cell 360 can be a perovskite solar cell, which includes: a first transport layer 362, a perovskite substrate 363, a second transport layer 364, a transparent conductive layer 365, and an antireflection layer (not shown). The first transport layer is directly opposite the bottom cell.

[0118] In some embodiments, the first transport layer may be either an electron transport layer or a hole transport layer, and the second transport layer may be either an electron transport layer or a hole transport layer.

[0119] Accordingly, another embodiment of this utility model provides a photovoltaic module, including the solar cell provided in the above embodiment, and the same or corresponding technical features as those in the above embodiment will not be described in detail here.

[0120] Figure 10 This is a schematic diagram of a photovoltaic module provided in another embodiment of the present invention.

[0121] refer to Figure 10 A photovoltaic module includes: a battery string, which is formed by connecting multiple solar cells as described in any of the above embodiments or tandem cells as described in the above embodiments; an encapsulating film 403 for covering the surface of the battery string; and a cover plate 404 for covering the surface of the encapsulating film away from the battery string.

[0122] Specifically, in some embodiments, multiple solar cells 40 can be electrically connected by a connecting member 402. The connecting member 402 is welded to a sub-grid on the solar cell, and the sub-grid includes a first edge grid line, a second edge grid line, and a middle grid line. The connecting member can also be welded to a first solder joint 20 or a second solder joint 30. The solar cell can be a solar cell as described in any of the above embodiments or a tandem solar cell as described in the above embodiments.

[0123] In some embodiments, there is no spacing between the solar cells, meaning that the solar cells overlap each other.

[0124] In some embodiments, the encapsulating film 403 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the solar cell, and the second encapsulating layer covers the other of the front or back sides of the solar cell. Specifically, at least one of the first encapsulating layer or the second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyethylene terephthalate (PET) film.

[0125] It is worth noting that the first encapsulation layer and the second encapsulation layer still have a dividing line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 403.

[0126] In some embodiments, the cover plate 404 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 404 facing the encapsulating film 403 can be an uneven surface, thereby increasing the utilization rate of incident light. The cover plate 404 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer and the second cover plate being opposite to the second encapsulation layer; or the first cover plate being opposite to one side of the solar cell and the second cover plate being opposite to the other side of the solar cell.

[0127] Those skilled in the art will understand that the above embodiments are specific examples of implementing this utility model, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this utility model. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this utility model; therefore, the protection scope of this utility model should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple solar cells; the solar cells include a cut surface (11), a first surface and a second surface, the two sides of the cut surface are respectively connected to the first surface and the second surface, the end of the solar cell near the cut surface has multiple first edge grid lines (111), the multiple first edge grid lines (111) are located on the first surface and are arranged at intervals along a first direction, and the spacing between adjacent first edge grid lines (111) is a first spacing D1; A passivation film (120) is provided, which at least covers the cut surface (11) and the first surface of the solar cell. The distance between the passivation film (120) covering the first surface is a second distance D2. The first distance D1 and the second distance D2 satisfy: 2D1≤D2<5D1. An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

2. The photovoltaic module according to claim 1, characterized in that, The distance between the first edge grid line closest to the cutting surface (11) and the cutting surface (11) is the third spacing D3, and the first spacing D1 and the third spacing D3 satisfy: 0.3D1<D3≤0.8D1.

3. The photovoltaic module according to claim 2, characterized in that, The range of the third spacing D3 is 0.2mm to 0.8mm.

4. The photovoltaic module according to claim 1, characterized in that, The first surface further includes a first edge (101); the solar cell further includes: a plurality of intermediate grid lines (113) and a second edge grid line (112), the second edge grid line (112) being close to the first edge (101), and the intermediate grid lines (113) being located between the second edge grid line (112) and the first edge grid line (111); the spacing between adjacent intermediate grid lines (113) is a fourth spacing D4, and the spacing between adjacent second edge grid lines (112) is a fifth spacing D5; the first spacing D1 and the fourth spacing D4 satisfy: D1 < D4 < 1.5D1; the first spacing D1 and the fifth spacing D5 satisfy: 0.5D1 < D5 ≤ 5D1.

5. The photovoltaic module according to claim 4, characterized in that, The passivation film (120) also covers the second edge gate line (112), and the second spacing D2 and the fifth spacing D5 satisfy: D5<D2≤3D5.

6. The photovoltaic module according to claim 4, characterized in that, The first surface further includes a second edge (102), which connects the first edge (101) and the cut surface (11). The distance between the end of the first gate line and the second edge (102) is a sixth spacing D6. The fourth spacing D4 and the sixth spacing D6 satisfy: 0.3D4<D6≤0.8D4. The first gate line is at least one of the first edge gate line (111), the second edge gate line (112), and the middle gate line (113).

7. The photovoltaic module according to claim 6, characterized in that, The first edge (101) and the second edge (102) have chamfers (103); the distance between the end of the second gate line and the chamfer (103) is a seventh spacing D7, the sixth spacing D6 and the fourth spacing D4 satisfy: 0.3D4<D6≤0.8D4; the seventh spacing and the fourth spacing satisfy: 0.4D7<D4≤0.9D7; the second gate line is at least one of the second edge gate line (112) and the middle gate line (113).

8. The photovoltaic module according to claim 7, characterized in that, The distance between the second edge grid line (112) closest to the first edge (101) and the first edge (101) is the eighth spacing D8, and the fourth spacing D4 and the eighth spacing satisfy: 0.3D8<D4≤0.8D8.

9. The photovoltaic module according to claim 4, characterized in that, The sum of the first spacing D1 and the fifth spacing D5 is greater than or equal to 0.6 times the fourth spacing D4 and less than 2 times the fourth spacing D4.

10. The photovoltaic module according to claim 4, characterized in that, The solar cell further includes a first harpoon structure (131) which is close to the first edge (101) and contacts N second edge grid lines (112), where 1 ≤ N ≤ 5.

11. The photovoltaic module according to claim 10, characterized in that, The second edge grid line (112) includes a first sub-grid line and a second sub-grid line. The first sub-grid line is close to the first edge (101). The first sub-grid line is divided into a first broken grid and a second broken grid arranged along the second direction by two harpoons of the first harpoon structure. The number of the first sub-grid lines is 1 to 3.

12. The photovoltaic module according to claim 1 or 10, characterized in that, The solar cell also includes a second harpoon structure, which is close to the cut surface and contacts M first edge grid lines (111), where N < M and 3 ≤ M ≤ 10.

13. The photovoltaic module according to claim 12, characterized in that, The first edge grid line (111) includes a third sub-grid line and a fourth sub-grid line. The fourth sub-grid line is close to the cutting surface. The third sub-grid line is divided into a third broken grid and a fourth broken grid arranged along the second direction by two harpoons of the second harpoon structure. The number of the third sub-grid lines is 1 to 5.

14. The photovoltaic module according to claim 13, characterized in that, The number of the third sub-grid lines is 1 to 3, and the fourth sub-grid line is divided into a fifth and a sixth broken grid arranged along the second direction by the two harpoons of the second harpoon structure; the number of the fourth sub-grid lines is 1 to 5.

15. The photovoltaic module according to claim 1, characterized in that, The passivation film includes a first part and a second part, the first part being located on the cut surface and the second part being located on the first surface, the thickness of the first part being greater than the thickness of the second part.

16. The photovoltaic module according to claim 1, characterized in that, The angle between the cutting surface and the first surface is either an obtuse angle or an acute angle; the angle between the cutting surface and the second surface is either an obtuse angle or an acute angle.

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