A photovoltaic module

Abstract

The application relates to the photovoltaic technical field, in particular to a photovoltaic module, which comprises cell pieces, a connecting point group and a solder strip, the solder strip is connected with adjacent cell pieces, and the connecting point group is arranged between the cell pieces and the solder strip; the connecting point group comprises a plurality of connecting points which are arranged at intervals along a first direction, and a plurality of connecting point groups are arranged at intervals along a second direction on the cell pieces; along the first direction, the cell pieces have a first area close to the center of the solder strip and a second area close to the end of the solder strip; the connecting point group comprises first connecting points located in the first area and second connecting points located in the second area, and the number of the first connecting points is more than that of the second connecting points. In the application, the number of the first connecting points is more than that of the second connecting points, so that the fixing effect of the connecting point group on the solder strip at the first area is greater than that at the second area, and then the solder strip is not easy to fall off or deviate from the preset position on the cell pieces, and the connection reliability of the solder strip and the cell pieces is high.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and more particularly to a photovoltaic module. Background Technology

[0002] Photovoltaic modules consist of solar cells and solder ribbons, which connect the cells in strings. String welding machines weld the solder ribbons onto the cells. Due to the high temperatures during welding, the cells are prone to warping, and even microcracks and fragmentation. To reduce the degree of cell warping and the probability of microcracks and fragmentation, an improved method involves pre-fixing the solder ribbons onto the cells, and then connecting the solder ribbons and cells through lamination at relatively lower temperatures.

[0003] The solar cell has adhesive dots that bond with the solder ribbon, pre-fixing it. However, the adhesive dots have limited fixing effect on the solder ribbon. The center of the solder ribbon corresponds to the gap between the two solar cells it connects to. Therefore, near the center of the solder ribbon, the pull force on the ribbon is greater, making it easy for the ribbon to detach from the solar cell or deviate from the preset position, thus preventing the ribbon from conducting current to the solar cell. Utility Model Content

[0004] This application provides a photovoltaic module to solve the technical problem that the solder ribbon is easy to fall off the solar cell or deviate from the preset position.

[0005] This application provides a photovoltaic module including solar cells, a group of connection points, and a solder ribbon. The solder ribbon connects adjacent solar cells, and the group of connection points is disposed between the solar cells and the solder ribbon. The group of connection points includes a plurality of connection points spaced apart along a first direction, and multiple rows of the group of connection points are spaced apart on the solar cells along a second direction. Along the first direction, the solar cell has a first region near the center of the solder ribbon and a second region near the end of the solder ribbon. The group of connection points includes a first connection point located in the first region and a second connection point located in the second region, wherein the number of the first connection points is greater than the number of the second connection points.

[0006] In one possible design, the number N1 of the first connection points in each column of the connection point group satisfies: 3≤N1≤7.

[0007] In one possible design, the first connection points are evenly distributed in the first region.

[0008] In one possible design, the distance d1 between adjacent first connection points satisfies: 1mm≤d1≤3mm.

[0009] In one possible design, the number N2 of the second connection points in each column of the connection point group satisfies: 1≤N2≤3.

[0010] In one possible design, the connection point located between the first region and the second region is an intermediate connection point, and the intermediate connection points in the odd-numbered sequence of connection point groups and the intermediate connection points in the even-numbered sequence of connection point groups are staggered in the second direction.

[0011] In one possible design, each column of the connection point group has one intermediate connection point.

[0012] In one possible design, along the first direction, the distance d2 between the intermediate connection points in the adjacent column of the connection point group satisfies: 5mm ≤ d2 ≤ 12mm.

[0013] In one possible design, along the second direction, the projections of the intermediate connection points in the odd-numbered groups of connection points coincide, and / or, along the second direction, the projections of the intermediate connection points in the even-numbered groups of connection points coincide.

[0014] In one possible design, along the first direction, the minimum distance d3 between the intermediate connection point and the first connection point satisfies: 5mm ≤ d3 ≤ 12mm.

[0015] In one possible design, along the first direction, the minimum distance d4 between the intermediate connection point and the second connection point satisfies: 5mm ≤ d4 ≤ 12mm.

[0016] In one possible design, harpoon structures are provided at both ends of the battery cell along the first direction; along the first direction, the minimum distance between the first connection point and the harpoon structure is equal to the minimum distance between the second connection point and the harpoon structure.

[0017] In one possible design, the battery cell is provided with a first grid line extending along a first direction, the number of the first grid lines being less than the number of columns of the connection point group, and a portion of the connection point group is disposed on the first grid line.

[0018] In one possible design, at least one column of the connection point group is provided between adjacent first grid lines.

[0019] In one possible design, when the number of connection point groups is even, two columns of connection point groups are arranged between the two middle first grid lines, and one column of connection point groups is arranged between other adjacent two first grid lines.

[0020] In one possible design, the battery cell is provided with a first grid line extending along a first direction, the number of the first grid lines being equal to the number of columns of the connection point group, the connection point group being disposed on the first grid line.

[0021] In one possible design, the first gate line includes a positive main gate and a negative main gate, which are staggered along a second direction; along the second direction, the first region and the second region are staggered.

[0022] In one possible design, the battery cell has a second grid line extending in a second direction, the second grid line has a pad, the second grid line breaks at the pad, and the connection point group contacts at least a portion of the pad.

[0023] In one possible design, the battery cell is provided with a second grid line extending along a second direction, the second grid line including a positive electrode grid and a negative electrode grid, the positive electrode grid and the negative electrode grid being located on the front and back sides of the battery cell, respectively; on the front side of the battery cell, the number of the first connection points is greater than the number of the first connection points on the back side of the battery cell.

[0024] In this application, by having more first connection points than second connection points, the fixing effect of the connection point group on the solder ribbon in the first region is greater than that in the second region. This makes it less likely for the solder ribbon to detach from the solar cell or deviate from its preset position, resulting in higher reliability of the connection between the solder ribbon and the solar cell. Furthermore, by rationally designing the distribution of connection points, the number of connection points on each solar cell is not increased, thus not increasing the production cost of the photovoltaic module.

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

[0026] Figure 1 This is a schematic diagram of the structure of the photovoltaic module provided in this application in one embodiment;

[0027] Figure 2 for Figure 1 A partial structural diagram of the battery cells and solder strips in the diagram;

[0028] Figure 3 for Figure 2 A schematic diagram of the structure of the battery cell in one embodiment;

[0029] Figure 4 for Figure 2 A schematic diagram of the structure of the battery cell in another embodiment;

[0030] Figure 5 for Figure 3 , Figure 4 A structural diagram of two adjacent columns of connection points in the diagram;

[0031] Figure 6 for Figure 2 A schematic diagram of the structure of the battery cell in another embodiment, wherein the number of columns of the connection point group is odd;

[0032] Figure 7 for Figure 2 A schematic diagram of the structure of the battery cell in another embodiment, wherein the number of columns of the connection point group is even;

[0033] Figure 8 for Figure 7 A magnified view of a portion of region I;

[0034] Figure 9 A schematic diagram of the structure of the photovoltaic module provided in this application in another embodiment;

[0035] Figure 10 for Figure 1 A partial structural diagram of the battery cells and solder strips in the diagram;

[0036] Figure 11 for Figure 10 A schematic diagram of the structure of the battery cell in one embodiment;

[0037] Figure 12 for Figure 10 A schematic diagram of the structure of the battery cell in another embodiment.

[0038] Figure label:

[0039] 1-Battery cell;

[0040] 1a - First region;

[0041] 1b - Second Region;

[0042] 11 - First grid line;

[0043] 12 - Second grid line;

[0044] 13-Harpoon structure;

[0045] 14 - Pads;

[0046] 2-Connection point group;

[0047] 21 - First connection point;

[0048] 22 - Second connection point;

[0049] 23 - Intermediate connection point;

[0050] 3-Welding strip;

[0051] 4-Front-side packaging structure;

[0052] 5-Front-side film layer;

[0053] 6-Backside film layer;

[0054] 7- Backside packaging structure.

[0055] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0056] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0057] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0058] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0059] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0060] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0061] This application provides a photovoltaic module, which includes solar cells 1, connection point groups 2, and solder ribbons 3. The solder ribbons 3 connect adjacent solar cells 1 to form a cell string. The connection point groups 2 are disposed between the solar cells 1 and the solder ribbons 3 to pre-fix the solder ribbons 3 onto the solar cells 1 before welding them to the solar cells 1. That is, a row of connection point groups 2 on the solar cells 1 corresponds to a solder ribbon 3 on the solar cells 1. The solar cells 1 have a front side and a back side opposite to each other along their thickness direction Z. The front side is the light-receiving surface of the solar cells 1, and the back side is the back-lighting surface of the solar cells 1.

[0062] Figure 1 This is a schematic diagram of the structure of the photovoltaic module provided in this application in one embodiment. Figure 1 As shown, the photovoltaic module also includes: a front encapsulation structure 4, a front film layer 5, a back film layer 6, and a back encapsulation structure 7. The front encapsulation structure 4, the front film layer 5, the back film layer 6, and the back encapsulation structure 7 encapsulate the cell string to ensure that the photovoltaic module has high mechanical strength, reduce the impact of hail, wind, mechanical vibration, etc. on the photovoltaic module, improve the sealing performance of the photovoltaic module, and enhance its corrosion resistance and safety.

[0063] Specifically, the front encapsulation structure 4 and the back encapsulation structure 7 can be one of rigid materials such as tempered glass, polyethylene terephthalate (PET), and polycarbonate (PC), or one of flexible materials such as polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), and polyvinylidene fluoride (PVDF). These materials have high light transmittance, which can improve the photoelectric conversion efficiency of the photovoltaic module and ensure the power output of the photovoltaic module. The front film layer 5 and the back film layer 6 can be one of the following materials: ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyvinyl butyral (PVB), EVA-POE-EVA co-extruded film (EPE), EVA-POE co-extruded film (EP).

[0064] In the production process of photovoltaic modules, firstly, solar cells 1 are prepared. Then, a set of connection points 2 is applied to the solar cells 1 using an adhesive applicator. Next, a solder ribbon 3 is placed on the solar cells 1, and the set of connection points 2 pre-fixes the solder ribbon 3 so that it does not move freely relative to the solar cells 1. Then, multiple solar cells 1 are connected into a solar cell string using the solder ribbon 3. A front film layer 5 and a front encapsulation structure 4 are set on the front side of the solar cell string, and a back film layer 6 and a back encapsulation structure 7 are placed on the back side of the solar cell string. Finally, the front encapsulation structure 4, the front film layer 5, the solar cell string, the back film layer 6, and the back encapsulation structure 7 are laminated to form a laminate.

[0065] During the lamination process, the solder ribbon 3 is alloyed with the electrodes on the cell 1, achieving low-temperature welding between the solder ribbon 3 and the cell 1. Since the lamination temperature is lower than the temperature at which the solder ribbon 3 is directly welded to the electrodes on the cell 1, high temperature can be avoided to prevent the cell 1 from warping, reducing the probability of microcracks and fragmentation in the cell 1, which is beneficial to improving the reliability of the produced photovoltaic modules.

[0066] Understandably, compared to directly welding the solder strip 3 to the battery cell 1, achieving low-temperature welding during lamination requires adapting to low-temperature solder strips with even lower melting points.

[0067] Figure 2 for Figure 1 A partial structural diagram of the battery cell 1 and solder ribbon 3. (See attached diagram.) Figure 1 and Figure 2 As shown, the electrodes on the solar cell 1 include positive grid lines and negative grid lines. For solar cells 1 where the positive grid lines and negative grid lines are located on the front and back sides respectively, such as emitter-back passivated cells (PERC), tunnel oxide passivated contact cells (TOPCON), heterojunction cells (HIT), perovskite solar cells (PSC), etc., the solder ribbon 3 extends from the front side of one solar cell 1 to the back side of another solar cell 1 or from the back side of one solar cell 1 to the front side of another solar cell 1 to achieve the connection of adjacent solar cells 1.

[0068] For PERC cells, along their thickness direction, the PERC cell sequentially includes a front surface silver electrode, a front surface silicon nitride passivation layer, a phosphorus emitter layer, a P-type substrate silicon layer, a local aluminum back field, a metallic aluminum back electrode, and a back passivation layer (Al2O3 / SiN). x PERC cells use a passivation film to passivate the back surface, replacing the all-aluminum back surface, which enhances light reflection within the silicon substrate and reduces the recombination rate on the back surface, thus improving the cell's photoelectric conversion efficiency by 0.5%-1%.

[0069] For a TOPCon cell, along its thickness direction, it sequentially comprises a silver electrode, a front-surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate silicon layer, a diffused doped layer, an ultrathin silicon oxide layer, doped polycrystalline silicon, silicon nitride, and the silver electrode. The back of the cell consists of an ultrathin silicon oxide layer (1nm–2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure blocks minority carrier recombination, increasing the cell's open-circuit voltage and short-circuit current. The ultrathin oxide layer allows majority carrier electrons to tunnel into the polycrystalline silicon layer while simultaneously blocking minority carrier recombination. The excellent passivation effect of the ultrathin silicon oxide and heavily doped silicon film causes band bending on the silicon wafer surface, creating a field passivation effect. This significantly increases the probability of electron tunneling, reduces contact resistance, and improves the cell's open-circuit voltage and short-circuit current, thereby enhancing the cell's photoelectric conversion efficiency.

[0070] For HIT cells, along their thickness direction, HIT cells sequentially include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type substrate silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0071] For a perovskite solar cell, along its thickness direction, the perovskite solar cell sequentially includes a substrate material, a conductive thin film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrodes with minimal loss, thus generating high photogenerated voltage and current, resulting in high photoelectric conversion efficiency.

[0072] Figure 3 for Figure 2 A schematic diagram of the structure of the battery cell 1 in one embodiment. Figure 4 for Figure 2 The diagram shows the structure of the battery cell 1 in another embodiment. The first direction X and the second direction Y are both perpendicular to the thickness direction Z of the battery cell 1. For example, one of the first direction X and the second direction Y is the length direction of the battery cell 1, and the other is the width direction of the battery cell 1. The first direction X and the second direction Y are perpendicular to each other.

[0073] like Figure 3As shown, the solar cell 1 has a first grid line 11 extending along a first direction X and a second grid line 12 extending along a second direction Y. For example, the first grid line 11 is the main grid, and the second grid line 12 is the fine grid, i.e., a main grid cell. Multiple first grid lines 11 are spaced apart along the second direction Y, and multiple second grid lines 12 are spaced apart along the first direction X. Each first grid line 11 is connected to multiple second grid lines 12. The photocurrent generated by the solar cell 1 can be collected by the second grid lines 12, and the photocurrent collected by the second grid lines 12 can be collected by the first grid lines 11. A pad 14 is provided on the first grid line 11, and a solder ribbon 3 is soldered to the pad 14, connecting the solder ribbon 3 to the first grid line 11. The photocurrent in the first grid line 11 can flow through the pad 14 to the solder ribbon 3, thereby conducting the current out of the solar cell 1. Connection point group 2 is set on the first grid line 11, and the number of first grid lines 11 is equal to the number of columns of connection point group 2, so that a welding strip 3 can be reliably pre-fixed on each first grid line 11.

[0074] Specifically, the first gate line 11 includes a positive main gate and a negative main gate, and the second gate line 12 includes a positive fine gate and a negative fine gate. The positive main gate and the positive fine gate are positive gate lines, and the negative main gate and the negative fine gate are negative gate lines. A plurality of pads 14 are arranged at intervals along the first direction X on the first gate line 11. The pads 14 can contact the second gate line 12 or be disposed between two second gate lines 12.

[0075] like Figure 4 As shown, the solar cell 1 only has a second grid line 12 extending along the second direction Y, meaning that the solar cell 1 does not have a first grid line 11, i.e., it is a gridless solar cell. The connection point group 2 is positioned on the solar cell 1 in a manner corresponding to that of a solar cell with a grid. The pad 14 is disposed on the second grid line 12, allowing the solder ribbon 3 to be directly connected to the second grid line 12. The photocurrent collected by the second grid line 12 can flow directly to the solder ribbon 3 through the pad 14, thereby extracting the current from the solar cell 1. Gridless solar cells can reduce the amount of paste used for printed electrodes, reduce the production cost of the solar cell 1, and reduce the shading of the grid lines on the surface of the solar cell 1, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 1.

[0076] like Figure 3 and Figure 4 As shown, the connection point group 2 includes a plurality of connection points spaced apart along a first direction X, and multiple rows of connection point groups 2 are spaced apart along a second direction Y on the battery cell 1; along the first direction X, the battery cell 1 has a first region 1a near the center of the solder strip 3 and a second region 1b near the end of the solder strip 3; the connection point group 2 includes a first connection point 21 located in the first region 1a and a second connection point 22 located in the second region 1b, with the number of first connection points 21 exceeding the number of second connection points 22. The connection points are adhesive dots, and their shapes can be square, rectangular, circular, elliptical, triangular, etc.

[0077] Since the center of the solder ribbon 3 corresponds to the gap between the two battery cells 1 it connects to, the pull-out force on the solder ribbon 3 is greater near the center and less near the end. By making the number of first connection points 21 greater than the number of second connection points 22, the fixing effect of the connection point group 2 on the solder ribbon 3 in the first region 1a is greater than that in the second region 1b. This makes it less likely for the solder ribbon 3 to fall off the battery cell 1 or deviate from the preset position, resulting in higher reliability of the connection between the solder ribbon 3 and the battery cell 1.

[0078] At the same time, by rationally designing the distribution of connection points, the number of connection points on each cell 1 will not increase, and thus the production cost of photovoltaic modules will not increase.

[0079] Specifically, in each column of connection point group 2, the number N1 of the first connection point 21 satisfies: 3 ≤ N1 ≤ 7. For example, in each column of connection point group 2, the number N1 of the first connection point 21 can be 3, 4, 5, 6, or 7.

[0080] In each column of connection point group 2, the number N1 of the first connection point 21 should not be too much or too little. If the number N1 of the first connection point 21 is too much (for example, more than 7), the paste required for printing the first connection point 21 will increase, and the cost required for producing photovoltaic modules will increase. If the number N1 of the first connection point 21 is too little (for example, less than 3), the fixing effect of the first connection point 21 on the center near the solder ribbon 3 will be weakened, the probability of the solder ribbon 3 falling off the cell 1 or deviating from the preset position will increase, and the connection reliability between the solder ribbon 3 and the cell 1 will be low.

[0081] Therefore, the number N1 of the first connection point 21 in each column of connection point group 2 should be selected within an appropriate range.

[0082] Optionally, in the first region 1a, the first connection points 21 are evenly distributed to facilitate the coating of the first connections 21. Optionally, in the first region 1a, along the direction away from the center of the solder strip 3, the distance between adjacent first connection points 21 gradually increases, so that the fixing effect of the first connection points 21 on the solder strip 3 varies with the magnitude of the pull-out force on the solder strip 3.

[0083] Furthermore, the number of first connection points 21 on the front side of the battery cell 1 is greater than the number of first connection points 21 on the back side of the battery cell 1. Since the solder ribbon 3 extends from the front side of one battery cell 1 to the back side of another battery cell 1 or from the back side of one battery cell 1 to the front side of another battery cell 1, the pull-out force on the portion of the solder ribbon 3 near the center on the front side of the battery cell 1 is greater than the pull-out force on the portion on the back side of the battery cell 1. Therefore, having more first connection points 21 on the front side of the battery cell 1 than on the back side of the battery cell 1 can ensure the fixing effect of the connection points on the solder ribbon 3 while reducing the overall number of connection points on the battery cell 1.

[0084] In some other embodiments, the number of first connection points 21 on the front side of the battery cell 1 is equal to the number of first connection points 21 on the back side of the battery cell 1. In still other embodiments, the number of first connection points 21 on the front side of the battery cell 1 is less than the number of first connection points 21 on the back side of the battery cell 1.

[0085] Specifically, in each column of connection point group 2, the number N2 of the second connection point 22 satisfies: 1 ≤ N2 ≤ 3. For example, in each column of connection point group 2, the number N2 of the second connection point 22 can be 1, 2, or 3.

[0086] In each column of connection point group 2, the number N2 of second connection points 22 should not be too much or too little. If the number N2 of second connection points 22 is too much (e.g., more than 3), the paste required for printing the second connection points 22 will increase, and the cost required for producing photovoltaic modules will increase. If the number N2 of second connection points 22 is too little (e.g., less than 1), there will be no second connection points 22 in the second region 1b, which will not fix the end of the solder ribbon 3. The end of the solder ribbon 3 will easily deviate from the preset position, which will cause the solder ribbon 3 to fail to conduct the current collected by the second grid line 12 to the cell 1.

[0087] Therefore, the number N2 of the second connection point 22 in each column of connection point group 2 should be selected within an appropriate range.

[0088] Figure 5 for Figure 3 , Figure 4 A schematic diagram of the structure of adjacent columns of connection points group 2. (See diagram below.) Figure 5 As shown, the distance d1 between adjacent first connection points 21 satisfies: 1mm ≤ d1 ≤ 3mm. For example, the specific distance d1 between adjacent first connection points 21 can be: 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, etc.

[0089] The distance d1 between adjacent first connection points 21 should not be too large or too small. If the distance d1 between adjacent first connection points 21 is too large (e.g., greater than 3 mm), the range of the first region 1a will be too large, the first connection points 21 will be more dispersed, the fixing effect on the center near the solder ribbon 3 will be weakened, the probability of the solder ribbon 3 falling off the battery cell 1 or deviating from the preset position will increase, and the connection reliability between the solder ribbon 3 and the battery cell 1 will be low. If the distance d1 between adjacent first connection points 21 is too small (e.g., less than 1 mm), the precision required for coating the first connection points 21 will be higher, the cost required for coating the first connection points 21 will increase, and the range of the first region 1a will be too small, the first connection points 21 will be more concentrated, which will also affect the fixing effect of the first connection points 21 on the center near the solder ribbon 3.

[0090] Therefore, the distance d1 between adjacent first connection points 21 should be selected within a suitable range.

[0091] Furthermore, such as Figures 3-5 As shown, the connection point between the first region 1a and the second region 1b is the intermediate connection point 23. The intermediate connection point 23 can pre-fix the welding strip 3 located between the first region 1a and the second region 1b to prevent the welding strip 3 from bending and deviating from the preset position.

[0092] The intermediate connection points 23 in the odd-numbered connection point group 2 and the intermediate connection points 23 in the even-numbered connection point group 2 are staggered in the second direction Y, thereby improving the uniformity of the distribution of intermediate connection points 23 on the cell 1. The uniformly distributed intermediate connection points 23 during lamination can enable the thermal stress to be released uniformly on the cell 1, reducing microcracks or deformation of the cell 1 caused by temperature gradient.

[0093] It is understandable that the intermediate connection point 23 in the odd-numbered column connection point group 2 and the intermediate connection point 23 in the even-numbered column connection point group 2 can also overlap in projection on the second direction Y, which facilitates the coating of the intermediate connection point 23.

[0094] Preferably, each column of connection point group 2 has an intermediate connection point 23, which serves to pre-fix the welding strip 3 while reducing the amount of paste required to print the intermediate connection point 23, thereby ensuring that setting the intermediate connection point 23 does not significantly increase the cost of producing photovoltaic modules.

[0095] Understandably, based on the distance between the first region 1a and the second region 1b, the number of intermediate connection points 23 in each column connection point group 2 can be appropriately increased. For example, the number of intermediate connection points 23 in each column connection point group 2 can be two, three, etc.

[0096] Preferably, along the second direction Y, the projections of the intermediate connection points 23 in the odd-numbered column connection point group 2 coincide, and / or, along the second direction Y, the projections of the intermediate connection points 23 in the even-numbered column connection point group 2 coincide, thereby facilitating the coating of the intermediate connection points 23 by coating the intermediate connection points 23 together with the intermediate connection points 23 in the odd-numbered column connection point group 2 and coating the intermediate connection points 23 in the even-numbered column connection point group 2.

[0097] like Figure 5 As shown, along the first direction X, the distance d2 between the intermediate connection points 23 in the adjacent column connection point group 2 satisfies: 5mm ≤ d2 ≤ 12mm. For example, the distance d2 between the intermediate connection points 23 in the adjacent column connection point group 2 can specifically be: 5mm, 5.2mm, 5.5mm, 5.8mm, 6mm, 6.2mm, 6.5mm, 6.8mm, 7mm, 7.2mm, 7.5mm, 7.8mm, 8mm, 8.2mm, 8.5mm, 8.8mm, 9mm, 9.2mm, 9.5mm, 9.8mm, 10mm, 10.2mm, 10.5mm, 10.8mm, 11mm, 11.2mm, 11.5mm, 11.8mm, 12mm, etc.

[0098] Along the first direction X, the distance d2 between the intermediate connection points 23 in the adjacent column connection point group 2 should not be too large or too small. If the distance d2 between the intermediate connection points 23 in the adjacent column connection point group 2 is too large (for example, greater than 12mm), the intermediate connection point 23 will be far away from the first region 1a or the second region 1b, making the pre-fixation of the welding strip 3 by the intermediate connection point 23 weak and unable to effectively prevent the welding strip 3 from bending and deviating from the preset position. If the distance d2 between the intermediate connection points 23 in the adjacent column connection point group 2 is too small (for example, less than 5mm), the uniformity of the distribution of the intermediate connection points 23 on the battery cell 1 will be reduced, thus failing to uniformly release the thermal stress on the battery cell 1 during lamination, which may easily cause microcracks or deformation of the battery cell 1.

[0099] Therefore, along the first direction X, the distance d2 between the intermediate connection points 23 in the adjacent column connection point group 2 should be selected within a suitable range.

[0100] like Figure 5As shown, along the first direction X, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 satisfies: 5mm ≤ d3 ≤ 12mm. For example, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 can specifically be: 5mm, 5.2mm, 5.5mm, 5.8mm, 6mm, 6.2mm, 6.5mm, 6.8mm, 7mm, 7.2mm, 7.5mm, 7.8mm, 8mm, 8.2mm, 8.5mm, 8.8mm, 9mm, 9.2mm, 9.5mm, 9.8mm, 10mm, 10.2mm, 10.5mm, 10.8mm, 11mm, 11.2mm, 11.5mm, 11.8mm, 12mm, etc.

[0101] Along the first direction X, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 should not be too large or too small. If the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 is too large (for example, greater than 12mm), the solder strip 3 between the intermediate connection point 23 and the first connection point 21 is prone to bending and deviating from the preset position. If the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 is too small (for example, less than 5mm), the distance between the intermediate connection point 23 and the second connection point 22 will be too large, and the solder strip 3 between the intermediate connection point 23 and the second connection point 22 will be prone to bending and deviating from the preset position.

[0102] Therefore, the minimum distance d3 between the intermediate connection point 23 and the first connection point 21 along the first direction X should be selected within a suitable range.

[0103] like Figure 5 As shown, along the first direction X, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 satisfies: 5mm ≤ d4 ≤ 12mm. For example, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 can specifically be: 5mm, 5.2mm, 5.5mm, 5.8mm, 6mm, 6.2mm, 6.5mm, 6.8mm, 7mm, 7.2mm, 7.5mm, 7.8mm, 8mm, 8.2mm, 8.5mm, 8.8mm, 9mm, 9.2mm, 9.5mm, 9.8mm, 10mm, 10.2mm, 10.5mm, 10.8mm, 11mm, 11.2mm, 11.5mm, 11.8mm, 12mm, etc.

[0104] Along the first direction X, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 should not be too large or too small. If the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 is too large (for example, greater than 12mm), the solder strip 3 between the intermediate connection point 23 and the second connection point 22 will easily bend and deviate from the preset position. If the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 is too small (for example, less than 5mm), the distance between the intermediate connection point 23 and the first connection point 21 will be too large, and the solder strip 3 between the intermediate connection point 23 and the first connection point 21 will easily bend and deviate from the preset position.

[0105] Therefore, the minimum distance d4 between the intermediate connection point 23 and the second connection point 22 along the first direction X should be selected within a suitable range.

[0106] like Figure 3 and Figure 4 As shown, along the first direction X, harpoon structures 13 are provided at both ends of the solar cell 1. The harpoon structures 13 can collect the current collected by the second grid line 12 located at the end of the solar cell 1 to ensure the photoelectric conversion efficiency of the photovoltaic module. For cells with a main grid, the harpoon structure 13 is connected to the first grid line 11; for cells without a main grid, the harpoon structure 13 is directly provided at both ends of the solar cell 1.

[0107] like Figure 5 As shown, along the first direction X, the minimum distance between the first connection point 21 and the harpoon structure 13 is equal to the minimum distance between the second connection point 22 and the harpoon structure 13. Thus, when coating the first connection point 21 and coating the second connection point 22, the same distance can be achieved by using the harpoon structure 13 to position the connection point, reducing the probability of incorrect coating position of the connection point.

[0108] Figure 6 for Figure 2 The schematic diagram of the structure of the battery cell 1 in another embodiment shows that the number of columns of the connection point group 2 is odd. Figure 7 for Figure 2 The schematic diagram of the structure of the battery cell 1 in another embodiment shows that the number of columns of the connection point group 2 is even.

[0109] like Figure 6 and Figure 7 As shown, the number of first grid lines 11 is less than the number of columns of connection point groups 2. Some connection point groups 2 are arranged on the first grid lines 11 to combine the advantages of grid-connected cells and gridless cells. By reducing the number of first grid lines 11 on the cell 1, the amount of paste required to print the first grid lines 11 can be reduced, thereby reducing the production cost of photovoltaic modules.

[0110] Specifically, at least one column of connection point groups 2 is provided between adjacent first grid lines 11. Depending on the actual operating conditions, one, two, three or more columns of connection point groups 2 can be provided between adjacent first grid lines 11 to balance the photoelectric conversion efficiency and production cost of photovoltaic modules.

[0111] like Figure 7 As shown, when the number of connection point groups 2 is even, two columns of connection point groups 2 are set between the two middle first grid lines 11, and one column of connection point groups 2 is set between the other two adjacent first grid lines 11. This ensures that the connection point groups 2 located at both ends of the battery cell 1 along the second direction Y are all set on the first grid line 11. That is, the solder strips 3 located at both ends of the battery cell 1 along the second direction Y are all connected to the first grid line 11, rather than directly to the second grid line 12, thereby ensuring the current output effect generated at both ends of the battery cell 1 in the second direction Y.

[0112] Figure 8 for Figure 7 A magnified view of a portion of region I. (See image below.) Figure 8 As shown, the second grid line 12 is disconnected at the pad 14, and the connection point group 2 contacts at least a portion of the pad 14. Disconnecting the second grid line 12 reduces the amount of paste required for printing the second grid line 12, thereby reducing the production cost of the photovoltaic module. To ensure the reliability of the connection between the pad 14 and the second grid line 12, the pad 14 can be H-shaped, with both ends of the H-shaped pad 14 corresponding to the second grid lines 12 on both sides. It is understood that the pad 14 can also be other shapes.

[0113] Figure 9 This is a schematic diagram of the structure of the photovoltaic module provided in this application in another embodiment. Figure 10 for Figure 1 A partial structural diagram of the battery cell 1 and solder ribbon 3. (See attached diagram.) Figure 9 and Figure 10 As shown, for a battery cell 1 where both the positive and negative grid lines are located on the back side, such as a back contact battery (BC) or a back contact stacked battery, the solder ribbon 3 extends from the back side of one battery cell 1 to the back side of another battery cell 1 to achieve the connection between adjacent battery cells 1.

[0114] For BC cells, the emitter, surface field, and metal electrodes are all located on the back of the cell and arranged in an interdigitated pattern. The front side of cell 1 uses SiN. x / SiO x The double-layer anti-reflection passivation film ensures that there are no metal electrodes blocking the front of the battery, allowing the battery cell 1 to receive more incident light, reducing optical losses and improving photoelectric conversion efficiency.

[0115] BC batteries can be further subdivided into interdigitated back contact (IBC), heterojunction back contact (HBC), and tunnel oxide back contact (TBC).

[0116] For a back-contact tandem solar cell, it includes a top cell, an intermediate connecting layer, and a bottom cell, with the intermediate connecting layer connecting the bottom and top cells. The top cell can be one of a perovskite solar cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell, or a gallium arsenide solar cell. The bottom cell is a BC cell. The intermediate connecting layer can be selected from a transparent material with a high refractive index, such as a transparent conductive metal oxide thin film (ITO). An effective intermediate connecting layer needs to have high light transmittance to reduce light reflection and absorption at the connecting layer interface, as well as good conductivity to reduce the impact of series resistance on device performance.

[0117] Figure 11 for Figure 10 A schematic diagram of the structure of battery cell 1. (See diagram below.) Figure 11 As shown, the positive and negative main grids are staggered along the second direction Y; along the second direction Y, the first region 1a and the second region 1b are staggered. Therefore, the above implementation can also be applied to cells with main grids (BC) and cells without main grids and back contact stacked cells.

[0118] Figure 12 for Figure 10 A schematic diagram of the structure of battery cell 1 in another embodiment. (See diagram below.) Figure 12 As shown, the battery cell 1 does not have a first grid line 11, and along the second direction Y, the first region 1a and the second region 1b are alternately distributed. Therefore, the above embodiment can also be applied to gridless BC batteries and gridless back contact stacked batteries.

[0119] It should be noted that, Figure 11 and Figure 12 The red and blue lines used to distinguish the first gate line 11 and the harpoon structure 13 of different polarities do not imply that the first gate line 11 and the harpoon structure 13 are red or blue. This application does not limit the colors of the first gate line 11 and the harpoon structure 13. It is understood that the colors of the positive main gate and the negative main gate can be the same or different, and the colors of the positive harpoon structure 13 and the negative harpoon structure 13 can be the same or different.

[0120] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photovoltaic module, characterized in that, The photovoltaic module includes a solar cell (1), a connection point group (2) and a solder strip (3), wherein the solder strip (3) connects adjacent solar cells (1), and the connection point group (2) is disposed between the solar cell (1) and the solder strip (3); The connection point group (2) includes a plurality of connection points spaced apart along a first direction (X), and multiple columns of the connection point group (2) are spaced apart along a second direction (Y) on the battery cell (1); Along the first direction (X), the battery cell (1) has a first region (1a) near the center of the solder strip (3) and a second region (1b) near the end of the solder strip (3); The connection point group (2) includes a first connection point (21) located in the first region (1a) and a second connection point (22) located in the second region (1b), wherein the number of the first connection points (21) is greater than the number of the second connection points (22).

2. The photovoltaic module according to claim 1, characterized in that, In each of the connection point groups (2), the number N1 of the first connection point (21) satisfies: 3≤N1≤7.

3. The photovoltaic module according to claim 1, characterized in that, In the first region (1a), the first connection points (21) are evenly distributed.

4. The photovoltaic module according to claim 3, characterized in that, The distance d1 between adjacent first connection points (21) satisfies: 1mm≤d1≤3mm.

5. The photovoltaic module according to claim 1, characterized in that, In each of the connection point groups (2), the number N2 of the second connection point (22) satisfies: 1≤N2≤3.

6. The photovoltaic module according to claim 1, characterized in that, The connection point located between the first region (1a) and the second region (1b) is an intermediate connection point (23). The intermediate connection points (23) in the odd-numbered sequence of the connection point group (2) and the intermediate connection points (23) in the even-numbered sequence of the connection point group (2) are staggered in the second direction (Y).

7. The photovoltaic module according to claim 6, characterized in that, Each of the connection point groups (2) has one intermediate connection point (23).

8. The photovoltaic module according to claim 7, characterized in that, Along the first direction (X), the distance d2 between the intermediate connection points (23) in the adjacent column of the connection point group (2) satisfies: 5mm≤d2≤12mm.

9. The photovoltaic module according to claim 6, characterized in that, Along the second direction (Y), the projections of the intermediate connection points (23) in the odd-numbered connection point groups (2) coincide, and / or, along the second direction (Y), the projections of the intermediate connection points (23) in the even-numbered connection point groups (2) coincide.

10. The photovoltaic module according to claim 6, characterized in that, Along the first direction (X), the minimum distance d3 between the intermediate connection point (23) and the first connection point (21) satisfies: 5mm≤d3≤12mm.

11. The photovoltaic module according to claim 6, characterized in that, Along the first direction (X), the minimum distance d4 between the intermediate connection point (23) and the second connection point (22) satisfies: 5mm≤d4≤12mm.

12. The photovoltaic module according to claim 1, characterized in that, Along the first direction (X), harpoon structures (13) are provided at both ends of the battery cell (1); Along the first direction (X), the minimum distance between the first connection point (21) and the harpoon structure (13) is equal to the minimum distance between the second connection point (22) and the harpoon structure (13).

13. The photovoltaic module according to any one of claims 1-12, characterized in that, The battery cell (1) is provided with a first grid line (11) extending along a first direction (X), the number of the first grid lines (11) is less than the number of columns of the connection point group (2), and part of the connection point group (2) is provided on the first grid line (11).

14. The photovoltaic module according to claim 13, characterized in that, At least one column of the connection point group (2) is provided between adjacent first grid lines (11).

15. The photovoltaic module according to claim 13, characterized in that, When the number of connection point groups (2) is even, two columns of connection point groups (2) are arranged between the two middle first grid lines (11), and one column of connection point groups (2) is arranged between other adjacent two first grid lines (11).

16. The photovoltaic module according to any one of claims 1-12, characterized in that, The battery cell (1) is provided with a first grid line (11) extending along a first direction (X), the number of the first grid lines (11) is equal to the number of columns of the connection point group (2), and the connection point group (2) is provided on the first grid line (11).

17. The photovoltaic module according to claim 16, characterized in that, The first gate line (11) includes a positive main gate and a negative main gate, which are staggered along the second direction (Y); Along the second direction (Y), the first region (1a) and the second region (1b) are staggered.

18. The photovoltaic module according to any one of claims 1-12, characterized in that, The battery cell (1) is provided with a second grid line (12) extending in a second direction (Y), and a pad (14) is provided on the second grid line (12). The second grid line (12) is disconnected at the pad (14), and the connection point group (2) is in contact with at least a portion of the pad (14).

19. The photovoltaic module according to any one of claims 1-12, characterized in that, The battery cell (1) is provided with a second grid line (12) extending along the second direction (Y). The second grid line (12) includes a positive grid and a negative grid, which are located on the front and back sides of the battery cell (1), respectively. On the front side of the battery cell (1), the number of the first connection points (21) is greater than that on the back side of the battery cell (1).

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