Photovoltaic cell and photovoltaic module

Abstract

The embodiment of the present application provides a photovoltaic cell and a photovoltaic module, the photovoltaic cell comprises a body, a secondary grid and a main grid, the body has a first edge and a second edge which are oppositely arranged along a first direction; the secondary grid is arranged on the body and extends along a second direction, and a plurality of secondary grids are arranged at intervals along the first direction; the main grid is arranged on the body and extends along the first direction, and is electrically connected with the plurality of secondary grids, along the first direction, a first welding point is arranged on one side of the main grid close to the first edge, and a second welding point is arranged on one side of the main grid close to the second edge; along the first direction, the distance L1 between the first welding point and the first edge satisfies: 3.5mm<=L1<5mm; and / or, along the first direction, the distance L2 between the second welding point and the second edge satisfies: 3.5mm<=L2<5mm. The above structure can increase the effective connection length and the effective connection area of the main grid and the welding strip, is beneficial to improving the current collection capacity of the welding strip on the main grid and the current collection capacity of the welding strip on the secondary grid of the edge part, and can further improve the power generation efficiency of the photovoltaic cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic cells, in particular to a photovoltaic cell and a photovoltaic module. BACKGROUND

[0002] The welding strip in the photovoltaic module is used to connect with the welding spot on the main grid of the photovoltaic cell to realize the series and parallel connection between adjacent photovoltaic cells, and plays a role in collecting and transmitting current.

[0003] In the structure of the existing photovoltaic cell, the distance between the end welding spot at both ends of the main grid and the edge of the photovoltaic cell is far, which leads to a short effective connection length of the main grid and the welding strip, and part of the current at the edge of the photovoltaic cell cannot be effectively collected by the welding strip, thereby affecting the efficiency of the photovoltaic cell. SUMMARY

[0004] Therefore, the present application provides a photovoltaic cell and a photovoltaic module to solve the problem of low efficiency of the photovoltaic cell in the prior art.

[0005] In a first aspect, an embodiment of the present application provides a photovoltaic cell, comprising: a body having a first edge and a second edge oppositely arranged along a first direction; a sub-grid arranged on the body, the sub-grid extending along a second direction, and a plurality of the sub- grids are arranged along the first direction at intervals; a main grid arranged on the body, the main grid extending along the first direction, and electrically connected with the plurality of sub- grids, along the first direction, a first welding spot is arranged on one side of the main grid close to the first edge, and a second welding spot is arranged on one side of the main grid close to the second edge; along the first direction, the distance L1 between the first welding spot and the first edge satisfies: 3.5mm≤L1<5mm; and / or, along the first direction, the distance L2 between the second welding spot and the second edge satisfies: 3.5mm≤L2<5mm; wherein the second direction is perpendicular to the first direction.

[0006] In a possible implementation manner, the main grid is further provided with a plurality of third welding spots; along the first direction, the plurality of third welding spots are distributed at intervals between the first welding spot and the second welding spot.

[0007] In a possible implementation manner, along the first direction, the distance L3 between any two adjacent third welding spots satisfies: 14mm≤L3≤15mm.

[0008] In a possible implementation, along the first direction, a distance L4 between the first solder joint and the third solder joint adjacent to the first solder joint satisfies: 18mm≤L4≤19mm; and / or, a distance L5 between the second solder joint and the third solder joint adjacent to the second solder joint satisfies: 18mm≤L5≤19mm.

[0009] In a possible implementation, the main grid includes a connecting portion between the first solder joint and the second solder joint, a first end portion between the first solder joint and the first edge, and a second end portion between the second solder joint and the second edge; two ends of the connecting portion along the first direction are connected with the first end portion and the second end portion, respectively.

[0010] In a possible implementation, when a distance L1 between the first solder joint and the first edge satisfies: 3.5mm≤L1<5mm, the first end portion is a fish-tail structure; the fish-tail structure includes a first busbar portion and a second busbar portion spaced along the second direction, and the first busbar portion and the second busbar portion are both connected with the connecting portion; the first busbar portion and the second busbar portion are electrically connected with a plurality of the auxiliary grids, respectively.

[0011] In a possible implementation, when a distance L1 between the first solder joint and the first edge satisfies: 3.5mm≤L1<5mm, the first end portion is a straight line structure extending along the first direction.

[0012] In a possible implementation, when a distance L2 between the second solder joint and the second edge satisfies: 3.5mm≤L2<5mm, the second end portion is a fish-tail structure; the fish-tail structure includes a first busbar portion and a second busbar portion spaced along the second direction, and the first busbar portion and the second busbar portion are both connected with the connecting portion; the first busbar portion and the second busbar portion are electrically connected with a plurality of the auxiliary grids, respectively.

[0013] In a possible implementation, when a distance L2 between the second solder joint and the second edge satisfies: 3.5mm≤L2<5mm, the second end portion is a straight line structure extending along the first direction.

[0014] In the second aspect, the embodiments of the present application provide a photovoltaic module, including a cell string, including a plurality of photovoltaic cell pieces, two adjacent photovoltaic cell pieces being connected through a solder strip, the photovoltaic cell piece being the photovoltaic cell piece described above; an encapsulation layer, used for covering a surface of the cell string; a cover plate, used for covering a surface of the encapsulation layer away from the cell string.

[0015] In the present application, when L1 satisfies 3.5mm≤L1<5mm, the distance between the first solder joint and the first edge is small, which is equivalent to moving the first solder joint outward, so as to increase the effective connection length and effective connection area of the main grid and the solder ribbon, thereby improving the current collection capability of the solder ribbon on the main grid, and improving the power generation efficiency of each photovoltaic cell. Moreover, since the charges on the auxiliary grid between the first edge and the first solder joint need to move to the first solder joint to be collected by the solder ribbon, when the distance between the first solder joint and the first edge is reduced, the moving path of the charges on the auxiliary grid close to the first edge is shortened, so as to improve the collection capability of the solder ribbon on the charges at the edge position, thereby facilitating the improvement of the efficiency of the photovoltaic cell. Similarly, when L2 satisfies 3.5mm≤L2<5mm, the distance between the second solder joint and the second edge is reduced, which is equivalent to moving the second solder joint outward, so as to increase the effective connection length and effective connection area of the main grid and the solder ribbon, thereby improving the current collection capability of the solder ribbon on the main grid, and improving the power generation efficiency of each photovoltaic cell. Moreover, since the charges on the auxiliary grid between the second edge and the second solder joint need to move to the second solder joint to be collected by the solder ribbon, when the distance between the second solder joint and the second edge is reduced, the moving path of the charges on the auxiliary grid close to the second edge is shortened, so as to improve the collection capability of the solder ribbon on the charges at the edge position, thereby facilitating the improvement of the efficiency of the photovoltaic cell. When L1 satisfies 3.5mm≤L1<5mm and L2 satisfies 3.5mm≤L2<5mm, which is equivalent to moving the end solder joints at both ends of the main grid outward, so as to maximize the effective connection length and effective connection area of the main grid and the solder ribbon, thereby facilitating the substantial improvement of the power generation efficiency of each photovoltaic cell, and improving the efficiency of the photovoltaic module.

[0016] Therefore, by limiting at least one of the distance L1 between the first solder joint and the first edge and the distance L2 between the second solder joint and the second edge to satisfy the range of greater than or equal to 3.5mm and less than 5mm, the present embodiment can realize the outward movement of the end solder joint on the main grid, so as to increase the effective connection length and effective connection area of the main grid and the solder ribbon, thereby facilitating the improvement of the current collection capability of the solder ribbon on the main grid and the current collection capability of the solder ribbon on the auxiliary grid at the edge position, and further improving the power generation efficiency of the photovoltaic cell.

[0017] It should be understood that the general description above and the detailed description below are only exemplary, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the 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.

[0019] Figure 1 A schematic diagram of the structure of the photovoltaic cell provided in this application in the first embodiment;

[0020] Figure 2 A schematic diagram of the structure of the photovoltaic cell provided in this application in a second embodiment;

[0021] Figure 3 A schematic diagram of the structure of the photovoltaic cell provided in this application in a third embodiment;

[0022] Figure 4 A schematic diagram of the structure of the photovoltaic cell provided in this application in the fourth embodiment;

[0023] Figure 5 This is a cross-sectional structural diagram of the photovoltaic module provided in this application.

[0024] Figure label:

[0025] 100-battery string;

[0026] 110-Photovoltaic Cells

[0027] 120 - Welding strip;

[0028] 200-Encapsulation layer;

[0029] 300-cover plate;

[0030] 1-Ontology;

[0031] 11-First Edge;

[0032] 12 - Second edge;

[0033] 2-Main gate;

[0034] 21-Connecting part;

[0035] 22-First end;

[0036] 23 - Second end;

[0037] 24-Harpoon structure;

[0038] 241-First Convergence Section;

[0039] 242 - Second Convergence Section;

[0040] 3 - secondary gate;

[0041] 4 - first solder point;

[0042] 5 - second solder point;

[0043] 6 - third solder point. DETAILED DESCRIPTION

[0044] For better understanding of the technical solutions of the present application, the embodiments of the present application are described in detail below in combination with the drawings.

[0045] It should be clear that the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0046] The terms used in the embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0047] It should be understood that the term "and / or" used herein is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0048] The embodiments of the present application provide a photovoltaic cell 110, as shown in Figure 1As shown, the photovoltaic cell includes a body 1, a main grid 2 and a sub-grid 3 arranged on the body 1. The sub-grid 3 is arranged on the body 1 and extends along the second direction Y for collecting and guiding the photo-generated current generated in the body 1. Specifically, a plurality of sub-grids 3 can be arranged on the surface of the body 1 along the first direction X, thereby increasing the current collection path and improving the current collection efficiency. At the same time, the sub-grid 3 can avoid the situation of large current density, thereby reducing the loss caused by local overheating of the photovoltaic cell 110. When a sub-grid 3 is damaged, the photo-generated current can also be collected by other sub-grids 3 to ensure that the photovoltaic cell 110 can work normally, thereby improving the stability and service life of the photovoltaic cell 110. The main grid 2 is arranged on the body 1 and extends along the first direction X. The main grid 2 is perpendicular to and electrically connected with the sub-grid 3. The main grid 2 is used for collecting the photo-generated current collected by the sub-grid 3 and outputting. Specifically, a plurality of main grids 2 can be arranged on the surface of the body 1 along the second direction Y, which can effectively reduce the resistance and improve the current transmission efficiency of the photovoltaic cell 110, thereby reducing the energy loss and improving the output power of the photovoltaic cell 110.

[0049] It should be noted that the first direction X is perpendicular to the second direction Y. The first direction X can be the width direction of the photovoltaic cell 110, and the second direction Y can be the length direction of the photovoltaic cell 110.

[0050] As shown in Figure 1 along the first direction X, the main grid 2 is provided with a plurality of welding points arranged at intervals. The welding points are used to connect with the solder strip to ensure that the main grid 2 and the solder strip are electrically connected, and the solder strip can collect the photo-generated current of the main grid 2. By arranging the welding points, the connection area of the main grid 2 and the solder strip can be increased, which is conducive to improving the welding yield of the solder strip, thereby improving the connection stability of the solder strip and the main grid 2. The shape of the welding point can be rectangular, rhombic, circular, elliptical, etc. These shapes can reduce the area of the welding point. Such design not only reduces the shielding of the body 1 by the welding point, but also reduces the consumption of silver paste and the manufacturing cost of the photovoltaic cell 110.

[0051] The body 1 has a first edge 11 and a second edge 12 arranged opposite along the first direction X. The welding points include a first welding point 4 close to the first edge 11 and a second welding point 5 close to the second edge 12. The first welding point 4 and the second welding point 5 are two end welding points of the main grid 2 along the first direction X. The distance between the first welding point 4 and the second welding point 5 determines the effective connection length of the solder strip and the main grid 2. As shown in Figure 1As shown, in the embodiment, the distance L1 between the first solder joint 4 and the first edge 11 along the first direction X satisfies: 3.5mm≤L1<5mm; and / or, the distance L2 between the second solder joint 5 and the second edge 12 along the first direction X satisfies: 3.5mm≤L2<5mm. Specifically, L1 can be 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm or 4.99mm, or other values within the above range, which are not limited in the embodiment; L2 can be 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm or 4.99mm, or other values within the above range, which are not limited in the embodiment.

[0052] When L1 satisfies 3.5mm≤L1<5mm, the distance between the first solder joint 4 and the first edge 11 is small, which is equivalent to moving the first solder joint 4 outward, and can increase the effective connection length and area of the solder ribbon with the main grid 2, thereby improving the collection ability of the solder ribbon to the current on the main grid 2, and improving the power generation efficiency of each photovoltaic cell piece 110. Moreover, the charges on the auxiliary grid 3 between the first edge 11 and the first solder joint 4 need to move to the first solder joint 4 to be collected by the solder ribbon, and when the distance between the first solder joint 4 and the first edge 11 is reduced, the moving path of the charges on the auxiliary grid 3 close to the first edge 11 is shortened, so that the collection ability of the solder ribbon to the charges at the edge position is improved, thereby facilitating the improvement of the efficiency of the photovoltaic cell piece 110.

[0053] Similarly, when L2 satisfies 3.5mm≤L2<5mm, the distance between the second solder joint 5 and the second edge 12 is reduced, which is equivalent to moving the second solder joint 5 outward, and can increase the effective connection length and area of the solder ribbon with the main grid 2, thereby improving the collection ability of the solder ribbon to the current on the main grid 2, and improving the power generation efficiency of each photovoltaic cell piece 110. Moreover, the charges on the auxiliary grid 3 between the second edge 12 and the second solder joint 5 need to move to the second solder joint 5 to be collected by the solder ribbon, and when the distance between the second solder joint 5 and the second edge 12 is reduced, the moving path of the charges on the auxiliary grid 3 close to the second edge 12 is shortened, so that the collection ability of the solder ribbon to the charges at the edge position is improved, thereby facilitating the improvement of the efficiency of the photovoltaic cell piece 110.

[0054] When L1 satisfies 3.5mm≤L1<5mm and L2 satisfies 3.5mm≤L2<5mm, it is equivalent to moving the end points of the two ends of the main grid 2 outward, which can maximize the effective connection length and area of the main grid 2 and the solder strip, and is beneficial to greatly improve the power generation efficiency of each photovoltaic cell 110, thereby improving the efficiency of the photovoltaic module.

[0055] Therefore, by limiting at least one of the distance L1 between the first solder point 4 and the first edge 11 and the distance L2 between the second solder point 5 and the second edge 12 to be greater than or equal to 3.5mm and less than 5mm, the embodiment can realize the outward movement of the end points on the main grid 2, thereby increasing the effective connection length and area of the main grid 2 and the solder strip, and is beneficial to improve the current collection capability of the solder strip on the main grid 2 and the current collection capability of the solder strip on the sub-grid 3 in the edge part, thereby improving the power generation efficiency of the photovoltaic cell 110.

[0056] When L1 satisfies 3.5mm≤L1<5mm, L2 can not satisfy 3.5mm≤L2<5mm, but should satisfy 5mm≤L2≤9mm to avoid the distance between the second solder point 5 and the second edge 12 being too large, thereby avoiding affecting the power generation efficiency of the photovoltaic cell 110 due to the too small effective connection length of the main grid 2 and the solder strip. Specifically, L2 can be 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm or 9mm, or other values within the above range, which are not limited by the embodiment.

[0057] Similarly, when L2 satisfies 3.5mm≤L2<5mm, L1 can not satisfy 3.5mm≤L1<5mm, but should satisfy 5mm≤L1≤9mm to avoid the distance between the first solder point 4 and the first edge 11 being too large, thereby avoiding affecting the power generation efficiency of the photovoltaic cell 110 due to the too small effective connection length of the main grid 2 and the solder strip. Specifically, L1 can be 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm or 9mm, or other values within the above range, which are not limited by the embodiment.

[0058] It should be noted that the photovoltaic cell 110 provided by the embodiment can be a whole cell, including but not limited to a square cell and a rectangular cell; or can be a cut cell, including but not limited to a two-piece, three-piece, four-piece, etc. The distance L1 between the first solder point 4 and the first edge 11 and the distance L2 between the second solder point 5 and the second edge 12 are not affected by the size and shape of the photovoltaic cell 110, and do not change with the size or shape of the photovoltaic cell 110.

[0059] ReferenceFigure 1 and Figure 2 The following section will take photovoltaic cell 110 as an example, which is divided into two sections, and will introduce the specific structure of photovoltaic cell 110 in detail.

[0060] like Figure 1 As shown, the solder joint also includes multiple third solder joints 6. Along the first direction X, the multiple third solder joints 6 are distributed at intervals between the first solder joint 4 and the second solder joint 5. By setting the third solder joints 6, the connection area between the main grid 2 and the solder strip can be increased, thereby improving the connection stability between the main grid 2 and the solder strip, which in turn helps to improve the solder strip's ability to collect current from the main grid 2. Moreover, by setting multiple third solder joints 6 between the first solder joint 4 and the second solder joint 5, the solder strip can be pre-positioned, facilitating the welding of the solder strip to the main grid 2 and reducing the risk of solder strip misalignment. The number of third solder joints 6 can be 4, 5, or 6. A smaller number of third solder joints 6 can reduce the shading of the main body 1 by the third solder joints 6, thereby helping to improve the light utilization rate of the main body 1 and thus helping to improve the power generation efficiency of the photovoltaic cell 110.

[0061] In one specific implementation, along the first direction X, the distance L3 between any two adjacent third solder points 6 satisfies: 14mm ≤ L3 ≤ 15mm. L3 can specifically be 14.1mm, 14.2mm, 14.3mm, 14.4mm, 14.5mm, 14.6mm, 14.7mm, 14.8mm, 14.9mm, or 15mm, or other values ​​within the above range; this embodiment does not impose any limitations on this.

[0062] If L3 is too small (e.g., less than 14mm), the distance between two adjacent third solder points 6 will be too small. With the positions of the first solder point 4 and the second solder point 5 fixed, this will result in an excessively large distance between the first solder point 4 and its adjacent third solder point 6. This will easily lead to poor connection when the main grid 2 between the first solder point 4 and its adjacent third solder point 6 is welded to the solder strip, and / or, it will also result in an excessively large distance between the second solder point 5 and its adjacent third solder point 6. This will easily lead to poor connection when the main grid 2 between the second solder point 5 and its adjacent third solder point 6 is welded to the solder strip. If L3 is too large (e.g., greater than 15mm), the distance between two adjacent third solder points 6 will be too large, easily leading to poor connection when the main grid 2 between the two adjacent third solder points 6 is welded to the solder strip.

[0063] Therefore, limiting the distance L3 between any two adjacent third solder points 6 to 14mm≤L3≤15mm is beneficial to improving the connection effect between the main grid 2 and the solder strip, thereby improving the current collection effect of the solder strip on the main grid 2, and thus improving the power generation efficiency of the photovoltaic cell 110.

[0064] In a specific embodiment, along the first direction X, the distance L4 between the first solder joint 4 and the third solder joint 6 adjacent thereto satisfies: 18mm≤L4≤19mm; and / or, the distance L5 between the second solder joint 5 and the third solder joint 6 adjacent thereto satisfies: 18mm≤L5≤19mm. Specifically, L4 can be 18mm, 18.1mm, 18.2mm, 18.3mm, 18.4mm, 18.5mm, 18.6mm, 18.7mm, 18.8mm, 18.9mm or 19mm, or other values within the above range, which are not limited in the present embodiment; L5 can be 18mm, 18.1mm, 18.2mm, 18.3mm, 18.4mm, 18.5mm, 18.6mm, 18.7mm, 18.8mm, 18.9mm or 19mm, or other values within the above range, which are not limited in the present embodiment.

[0065] When L4 satisfies 18mm≤L4≤19mm, L1 can satisfy 3.5mm≤L1<5mm, and if L4 is too large (e.g. greater than 19mm), the distance between the first solder joint 4 and the third solder joint 6 adjacent thereto is too large, which leads to poor connection between the busbar 2 between the first solder joint 4 and the third solder joint 6 adjacent thereto and the solder ribbon when soldering; if L4 is too small (e.g. less than 18mm), the distance between the two adjacent third solder joints 6 is too large, which leads to poor connection between the busbar 2 between the two adjacent third solder joints 6 and the solder ribbon when soldering.

[0066] Therefore, limiting the distance L4 between the first solder joint 4 and the third solder joint 6 adjacent thereto to satisfy 18mm≤L4≤19mm can ensure that the distance between the first solder joint 4 and the first edge 11 satisfies 3.5mm≤L1<5mm, and is conducive to improving the connection effect between the busbar 2 and the solder ribbon, thereby improving the current collection effect of the solder ribbon on the busbar 2, and further improving the power generation efficiency of the photovoltaic cell piece 110.

[0067] Similarly, when L5 satisfies 18mm≤L5≤19mm, L2 can satisfy 3.5mm≤L2<5mm, and if L5 is too large (e.g. greater than 19mm), the distance between the second solder joint 5 and the third solder joint 6 adjacent thereto is too large, which leads to poor connection between the busbar 2 between the second solder joint 5 and the third solder joint 6 adjacent thereto and the solder ribbon when soldering; if L5 is too small (e.g. less than 18mm), the distance between the two adjacent third solder joints 6 is too large, which leads to poor connection between the busbar 2 between the two adjacent third solder joints 6 and the solder ribbon when soldering.

[0068] Therefore, limiting the distance L5 between the second solder point 5 and the adjacent third solder point 6 to 18mm≤L5≤19mm ensures that the distance between the second solder point 5 and the second edge 12 is 3.5mm≤L2<5mm, which is beneficial to improving the connection effect between the main grid 2 and the solder strip, thereby improving the current collection effect of the solder strip on the main grid 2, and thus improving the power generation efficiency of the photovoltaic cell 110.

[0069] When L4 satisfies 18mm≤L4≤19mm and L5 satisfies 18mm≤L5≤19mm, it can ensure that the effective connection length and effective connection area between the main busbar 2 and the welding strip are maximized, and also reduce the risk of poor connection when the main busbar 2 and the welding strip are welded. This can not only improve the power generation efficiency of the photovoltaic cell 110, but also improve the working stability of the photovoltaic cell 110.

[0070] like Figure 1 As shown, the main gate 2 includes a connecting portion 21 located between the first solder point 4 and the second solder point 5, a first end portion 22 located between the first solder point 4 and the first edge 11, and a second end portion 23 located between the second solder point 5 and the second edge 12. The two ends of the connecting portion 21 along the first direction X are respectively connected to the first end portion 22 and the second end portion 23. Specifically, the first end portion 22 is connected to the connecting portion 21 through the first solder point 4. The first end portion 22 is used to collect the current on the sub-gate 3 located between the first edge 11 and the first solder point 4, and to collect and transmit the current to the connecting portion 21. The second end portion 23 is connected to the connecting portion 21 through the second solder point 5. The second end portion 23 is used to collect the current on the sub-gate 3 located between the second edge 12 and the second solder point 5, and to collect and transmit the current to the connecting portion 21. Multiple third solder points 6 are disposed on the connecting portion 21. The connecting portion 21 is used to weld to the solder strip and to collect and transmit the current on the main gate 2 to the solder strip.

[0071] In a specific embodiment, when L1 satisfies 3.5mm≤L1<5mm, the first end portion 22 can be a fish-tail structure 24 comprising a first busbar 241 and a second busbar 242 spaced apart along the second direction Y, both of which are connected with the connecting portion 21, and the first busbar 241 and the second busbar 242 are respectively electrically connected with the plurality of sub-grids 3. The first busbar 241 and the second busbar 242 can respectively collect the current on the plurality of sub-grids 3, which is conducive to improving the current collecting capacity of the first end portion 22 on the sub-grids 3 between the first edge 11 and the first soldering point 4, thereby improving the power generation efficiency of the photovoltaic cell piece 110. Moreover, when the first end portion 22 is the fish-tail structure 24, it has stronger compression resistance, and if one of the first busbar 241 and the second busbar 242 fails, the other one can still work normally, which is conducive to improving the service life and stability of the first end portion 22. In addition, since L1 satisfies 3.5mm≤L1<5mm, the length of the fish-tail structure 24 in the first direction X should be less than or equal to L1, which means that the length of the fish-tail structure 24 is small, which is conducive to reducing the consumption of silver paste and reducing the manufacturing cost of the photovoltaic cell piece 110.

[0072] In another specific embodiment, when L1 satisfies 3.5mm≤L1<5mm, the first end portion 22 can also be a straight line structure extending along the first direction X. Compared with the fish-tail structure 24, the straight line structure can further reduce the consumption of silver paste, thereby further reducing the manufacturing cost of the photovoltaic cell piece 110. Moreover, the extension direction of the straight line structure can be parallel to the extension direction of the solder strip, and when the solder strip is welded and connected with the main grid 2, the solder strip between the first edge 11 and the first soldering point 4 can be in contact with the straight line structure, which is equivalent to further extending the connection length of the main grid 2 and the solder strip, which can shorten the movement path of the electric charge on the sub-grid 3 between the first soldering point 4 and the first edge 11 to the solder strip, thereby further improving the current collecting capacity of the solder strip on the photovoltaic cell piece 110.

[0073] As Figure 1As shown, in one specific embodiment, when L2 satisfies 3.5mm≤L2<5mm, the second end 23 is a harpoon structure 24. The harpoon structure 24 includes a first busbar 241 and a second busbar 242 spaced apart along the second direction Y. Both the first busbar 241 and the second busbar 242 are connected to the connecting part 21, and are electrically connected to multiple sub-grids 3 respectively. The first busbar 241 and the second busbar 242 can respectively collect the current on multiple sub-grids 3, which is beneficial to improving the current collection capability of the second end 23 on the sub-grids 3 located between the second edge 12 and the second solder point 5, thereby improving the power generation efficiency of the photovoltaic cell 110. Moreover, when the second end 23 is a harpoon structure 24, its compressive strength is stronger. If one of the first busbar 241 and the second busbar 242 fails, the other can still work normally, which is beneficial to improving the service life and stability of the second end 23. Furthermore, since L2 satisfies 3.5mm≤L2<5mm, the length of the harpoon structure 24 in the first direction X should be less than or equal to L2, which means that the length of the harpoon structure 24 is small, which helps to reduce the consumption of silver paste and reduce the manufacturing cost of photovoltaic cell 110.

[0074] like Figure 2 As shown, in another specific embodiment, when L2 satisfies 3.5mm≤L2<5mm, the second end 23 can also be a straight structure extending along the first direction X. Compared with the harpoon structure 24, the straight structure can further reduce the consumption of silver paste, thereby further reducing the manufacturing cost of the photovoltaic cell 110. Moreover, the extension direction of the straight structure can be parallel to the extension direction of the solder strip. When the solder strip is welded to the main grid 2, the solder strip located between the second edge 12 and the second solder point 5 can form contact with the straight structure, which is equivalent to further extending the connection length between the main grid 2 and the solder strip. Compared with the harpoon structure 24, it can shorten the movement path of the charge on the sub-grid 3 located between the second solder point 5 and the second edge 12 to reach the solder strip, thereby further improving the solder strip's ability to collect current on the photovoltaic cell 110.

[0075] In summary, when L1 satisfies 3.5mm≤L1<5mm, the first end 22 can be a harpoon structure 24 or a straight structure; when L2 satisfies 3.5mm≤L2<5mm, the second end 23 can be a harpoon structure 24 or a straight structure. Therefore, when L1 satisfies 3.5mm≤L1<5mm and L2 satisfies 3.5mm≤L2<5mm, both the first end 22 and the second end 23 can be harpoon structures 24, or both can be straight structures, or one can be a harpoon structure 24 and the other can be a straight structure. This embodiment does not impose any restrictions on this.

[0076] In addition, when the photovoltaic cell 110 is a bifacial cell, the main grid 2 and the auxiliary grid 3 are arranged on the front surface (light-receiving surface) and the back surface (light-reflecting surface) of the photovoltaic cell 110, that is, the first soldering point 4 and the second soldering point 5 are arranged on the front surface and the back surface of the photovoltaic cell 110. The structure of the first soldering point 4 on the front surface can be the same as or different from the structure of the first soldering point 4 on the back surface, and the structure of the second soldering point 5 on the front surface can be the same as or different from the structure of the second soldering point 5 on the back surface, that is, for the same photovoltaic cell 110, the main grid 2 on the front surface and the main grid 2 on the back surface can be a symmetric structure or an asymmetric structure, which is not limited in the embodiment.

[0077] In addition, since the photovoltaic cell 110 shown in the embodiment is a two-piece cell, the structure of the whole cell before being cut into pieces can be the structure shown in Figure 4 or Figure 5 Along the first direction X, both ends of the whole cell are the second edge 12, the soldering points close to the second edge at both ends are the second soldering point 5, the middle part of the whole cell has two first edges 11, and the two rows of soldering points arranged oppositely in the middle part of the whole cell are the first soldering point 4. Along the first direction X, both ends of the whole cell have the second end part 23, the second end part 23 at both ends can be the fish-tail structure 24, or be a straight line structure, or one be the fish-tail structure 24 and the other be the straight line structure; the middle part of the whole cell has two rows of first end parts 22 arranged oppositely, the two rows of first end parts 22 can be the fish-tail structure 24, or be a straight line structure, or one row be the fish-tail structure 24 and the other row be the straight line structure. The whole cell includes two two-piece cells, and the two two-piece cells can be a symmetric structure (such as the structure shown in Figure 4 or Figure 5 with respect to the second direction Y) or an asymmetric structure, which is not limited in the embodiment.

[0078] The type of the photovoltaic cell 110 is not limited in the embodiment, and the type of the photovoltaic cell 110 includes but is not limited to a passivated emitter rear cell (PERC), a tunnel oxide passivated contact (TOPCon), a heterojunction with intrinsic thin-film (HJT), an interdigitated back contact (IBC), a perovskite cell, and the like.

[0079] For the PERC cell, along its thickness direction, the PERC cell includes in turn the front surface metal silver electrode, the front surface silicon nitride passivation layer, the phosphorus layer emitter, the P-type base silicon layer, the local aluminum back field, the metal aluminum back electrode, and the back passivation layer (Al2O3 / SiNx). The PERC cell uses a passivation film to passivate the back surface, replaces the full aluminum back field, enhances the internal back reflection of light in the silicon base, reduces the back surface recombination rate, and improves the efficiency of the cell by 0.5%-1%.

[0080] For the TOPCon cell, along its thickness direction, the TOPCon cell includes in turn the metal silver electrode, the front surface silicon nitride passivation layer, the boron-doped emitter, the N-type base silicon layer, the diffusion-doped layer, the ultra-thin silicon oxide, the doped polysilicon, the silicon nitride, and the metal silver electrode. The back surface of the cell is composed of an ultra-thin silicon oxide layer (1 nm-2 nm) and a phosphorus-doped microcrystalline / amorphous mixed Si thin film, which together form a passivation contact structure. This structure can block the recombination of minority carriers, improve the open-circuit voltage and short-circuit current of the cell. The ultra-thin oxide layer allows the majority carrier electrons to tunnel into the polysilicon layer while blocking the recombination of minority carriers. The good passivation effect of the ultra-thin silicon oxide and the heavily doped silicon thin film causes the energy band of the silicon wafer surface to bend, thereby forming a field passivation effect. The probability of electron tunneling increases significantly, the contact resistance decreases, and the open-circuit voltage and short-circuit current of the cell are improved, thereby improving the conversion efficiency of the cell.

[0081] For the HJT cell, along its thickness direction, the HJT cell includes in turn the front low-temperature silver electrode, the front conductive thin film, the N-type amorphous silicon thin film, the intrinsic amorphous silicon thin film, the N-type base silicon layer, the intrinsic amorphous silicon thin film, the P-type amorphous silicon thin film, the back conductive thin film, and the back low-temperature silver electrode.

[0082] For the IBC cell, along its thickness direction, the IBC cell includes in turn the silicon nitride back layer, the N+ front surface field, the N-type base silicon layer, the P+ emitter, the N+ back field, the aluminum oxide passivation layer, the silicon nitride anti-reflection layer, and the metal silver electrode. The IBC cell uses ion implantation technology to obtain P and N regions with good uniformity and accurately controllable junction depth. The cell has no grid line on the front surface, which can eliminate the shading current loss of the metal electrode, maximize the utilization of incident photons, and increase the short-circuit current by about 7% compared with the conventional solar cell. Due to the back contact structure, the grid line proportion can be appropriately widened, thereby reducing the series resistance and having a high fill factor. The surface passivation and surface light trapping structure can be optimally designed to obtain a low front surface recombination rate and surface reflection.

[0083] For the perovskite battery, along the thickness direction, the perovskite battery comprises a substrate material, a conductive film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode in sequence. The perovskite material has a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, the electrons are easily collected by the electrode and have less loss, so that a high photovoltage and current can be generated, and the perovskite exhibits a high photoelectric conversion efficiency.

[0084] As shown in Figure 5 The embodiments of the present application also provide a photovoltaic module, which comprises a cell string 100, an encapsulation layer 200, and a cover plate 300. The cell string 100 is composed of a plurality of photovoltaic cell pieces 110 connected by solder strips 120. The photovoltaic cell piece 110 is the photovoltaic cell piece 110 described in the above embodiments. The encapsulation layer 200 is used to cover the surface of the cell string 100. The cover plate 300 is used to cover the surface of the encapsulation layer 200 away from the cell string 100.

[0085] Specifically, the photovoltaic cell pieces 110 are electrically connected in the form of a whole piece or multiple pieces to form a plurality of cell strings 100, and the plurality of cell strings 100 are electrically connected in series and / or parallel. Specifically, the plurality of cell strings 100 can be electrically connected by the solder strips 120. The encapsulation layer 200 covers the front surface and the back surface of the photovoltaic cell piece 110. Specifically, the encapsulation layer 200 can be an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene copolymer (POE) film, a polyethylene terephthalate (PET) film, or a polyvinyl butyral (PVB) organic encapsulation film. The cover plate 300 can be a glass cover plate, a plastic cover plate, or a cover plate 300 with a light transmission function. The surface of the cover plate 300 facing the encapsulation layer 200 can be a concave-convex surface, thereby increasing the utilization rate of incident light.

[0086] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photovoltaic cell, characterized by, include: The body (1) has a first edge (11) and a second edge (12) disposed opposite to each other along a first direction; Sub-gates (3) are disposed on the body (1), the sub-gates (3) extend along the second direction, and multiple sub-gates (3) are spaced apart along the first direction; A main grid (2) is disposed on the body (1). The main grid (2) extends along the first direction and is electrically connected to a plurality of sub-grids (3). Along the first direction, a first solder point (4) is provided on the side of the main grid (2) near the first edge (11), and a second solder point (5) is provided on the side of the main grid (2) near the second edge (12). Along the first direction, the distance L1 between the first solder point (4) and the first edge (11) satisfies: 3.5mm≤L1<5mm, and / or, along the first direction, the distance L2 between the second solder point (5) and the second edge (12) satisfies: 3.5mm≤L2<5mm; The main grid (2) is also provided with a plurality of third solder points (6). Along the first direction, the plurality of third solder points (6) are distributed at intervals between the first solder point (4) and the second solder point (5). The distance L3 between any two adjacent third solder points (6) satisfies: 14mm≤L3≤15mm. Along the first direction, the distance L4 between the first solder point (4) and the adjacent third solder point (6) satisfies: 18mm≤L4≤19mm, and / or, along the first direction, the distance L5 between the second solder point (5) and the adjacent third solder point (6) satisfies: 18mm≤L5≤19mm; The second direction is perpendicular to the first direction.

2. The photovoltaic cell of claim 1, wherein, The main grid (2) includes a connecting portion (21) located between the first solder point (4) and the second solder point (5), a first end portion (22) located between the first solder point (4) and the first edge (11), and a second end portion (23) located between the second solder point (5) and the second edge (12). The connecting part (21) is connected to the first end (22) and the second end (23) at both ends along the first direction, respectively.

3. The photovoltaic cell of claim 2, wherein, When the distance L1 between the first solder point (4) and the first edge (11) satisfies: 3.5mm≤L1<5mm, the first end (22) is a harpoon structure (24). The harpoon structure (24) includes a first confluence portion (241) and a second confluence portion (242) spaced apart along the second direction, and both the first confluence portion (241) and the second confluence portion (242) are connected to the connecting portion (21); The first busbar (241) and the second busbar (242) are electrically connected to the plurality of sub-gates (3), respectively.

4. The photovoltaic cell of claim 2, wherein, When the distance L1 between the first solder joint (4) and the first edge (11) satisfies 3.5mm≤L1<5mm, the first end (22) is a straight structure extending along the first direction.

5. The photovoltaic cell of claim 2, wherein, The distance L2 between the second welding point (5) and the second edge (12) satisfies: 3.5mm≤L2<5mm, and the second end portion (23) is a fish-tail structure (24); The fish-tail structure (24) comprises a first converging portion (241) and a second converging portion (242) which are arranged at intervals along the second direction, and the first converging portion (241) and the second converging portion (242) are connected with the connecting portion (21); The first converging portion (241) and the second converging portion (242) are respectively electrically connected with a plurality of the auxiliary grids (3).

6. The photovoltaic cell of claim 2, wherein, The distance L2 between the second welding point (5) and the second edge (12) satisfies: 3.5mm≤L2<5mm, and the second end portion (23) is a straight line structure extending along the first direction.

7. A photovoltaic module, characterized by Comprise: A battery string (100) comprising a plurality of photovoltaic cell pieces (110), two adjacent photovoltaic cell pieces (110) being connected by a welding strip (120), the photovoltaic cell piece (110) being the photovoltaic cell piece (110) of any one of claims 1-6; An encapsulation layer (200) for covering the surface of the battery string (100); A cover plate (300) for covering the surface of the encapsulation layer (200) away from the battery string (100).

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