Photovoltaic module

Abstract

The invention provides a photovoltaic module, and belongs to the technical field of photovoltaics. The photovoltaic module comprises a battery body; a plurality of collector electrodes on at least one surface of the battery body; the plurality of current collection electrodes are arranged at intervals in a first direction and extend along a second direction intersected with the first direction; the plurality of electric connecting wires extend along the first direction and are connected with the adjacent battery bodies, and the electric connecting wires are fixedly and electrically connected with the plurality of current collecting electrodes; the plurality of bonding parts are positioned on at least one surface of the battery body and are used for bonding the electric connecting wires and the battery body, and the bonding parts and the surface of the battery body are provided with contact areas; wherein the contact area is provided with a first end and a second end in a second direction; in the second direction, the distance between the first end or the second end of the bonding part and the electric connecting wire is A, the width of the electric connecting wire in the second direction is X, A = aX, and a is larger than or equal to 2 and smaller than or equal to 8.

Description

Technical Field

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

[0002] With the development and widespread application of solar cell technology, photovoltaic power generation has become one of the more competitive forms of energy in the future. Solar cells are divided into various types based on different cell structures, such as Passivated Emitter and Rear Cell (PERC) cells, Tunnel Oxide Passivated Contact (TOPCon) cells, Heterojunction with Intrinsic Thin-layer (HJT) cells, and Interdigitated Back Contact (IBC) cells.

[0003] The production cost and power generation of photovoltaic cells have become major factors restricting their development. In particular, the metal paste required for the grid lines of the cells accounts for a relatively high cost. Due to the high cost of metal paste, attempts to reduce the number of grid lines or reduce the width of the grid lines can reduce the production cost of the cells, expand the light-receiving area of ​​the cells, and improve the photoelectric conversion efficiency.

[0004] The thin grids (also called collector electrodes) on the solar cells are connected to the circuit via electrical wires (also called solder ribbons). This arrangement limits the connection between the wires and the solar cells, resulting in poor connection strength for the photovoltaic module, affecting the long-term reliability of the module. Summary of the Invention

[0005] In view of this, in order to at least partially solve the above-mentioned technical problems, the present application provides a photovoltaic module.

[0006] According to an embodiment of one aspect of the present application, a photovoltaic module is provided, comprising: a battery body; a plurality of collecting electrodes located on at least one surface of the battery body; the plurality of collecting electrodes are spaced apart in a first direction and extend along a second direction intersecting the first direction; a plurality of electrical connection lines extending along the first direction and connecting adjacent battery bodies, the electrical connection lines being electrically connected to the plurality of collecting electrodes; a plurality of bonding portions located on at least one surface of the battery body, bonding the electrical connection lines and the battery body; the bonding portions having a contact area with the surface of the battery body; the contact area having a first end and a second end in the second direction; along the second direction, the first end or the second end of the bonding portion is at a distance A from the electrical connection line, and the width of the electrical connection line along the second direction is X, A=aX, 2≤a≤8.

[0007] The photovoltaic assembly provided by the above-mentioned embodiments of the present application, by providing multiple bonding portions, helps to improve the bonding force between the electrical connection wires and the battery body, improve the yield rate of the photovoltaic assembly, and thus improve the long-term reliability of the photovoltaic assembly. By adjusting the ratio between A and X within the aforementioned range, the present application helps to strengthen the bonding strength between the electrical connection wires and the battery body, and reduces the risk of the electrical connection wires falling off due to thermal expansion and contraction or mechanical impact. At the same time, it limits the blocking of the conductive path by the bonding portion, reduces the occupation of the effective conductive cross-sectional area of ​​the collector electrode and the electrical connection wire by the bonding portion, reduces the series resistance, and further improves the yield rate and reliability of the assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings, in which:

[0009] Figure 1 A partial top view of a photovoltaic module according to an embodiment of the present application is shown;

[0010] Figure 2 A cross-sectional schematic diagram of a bonding portion according to an embodiment of the present application is shown;

[0011] Figure 3 A schematic cross-sectional view of the first sub-section and the second sub-section of an embodiment of the present application is shown;

[0012] Figure 4 shows a cross-sectional view of a bonding portion according to an embodiment of the present application;

[0013] Figure 5 A cross-sectional view of a bonding portion according to another embodiment of the present application is shown;

[0014] Figure 6 A partial top view of a bonding portion according to an embodiment of the present application is shown;

[0015] Figure 7 A partial top view of a bonding portion according to another embodiment of the present application is shown;

[0016] Figure 8 A partial top view of a photovoltaic assembly near an edge according to an embodiment of the present application is shown.

[0017] In the drawings, the meanings of the reference numerals are as follows:

[0018] 1. Battery body;

[0019] 2. Collecting electrode;

[0020] 3. Electrical connection wires;

[0021] 4. Bonding part;

[0022] 41-contact area;

[0023] 411-First subsection;

[0024] 412-Second subsection;

[0025] 42-first end;

[0026] 43-second end;

[0027] A. the distance between the first end or the second end of the bonding portion and the electrical connection line;

[0028] A1, the distance between the first end and the electrical connection line;

[0029] A2, the distance between the second end and the electrical connection line;

[0030] X, the width of the electrical connection line along the second direction;

[0031] T, the distance between the two ends of the contact area of ​​the bonding portion along the first direction (on either side of the electrical connection line along the second direction);

[0032] T1, the distance between the two ends of the first sub-portion of the contact area along the first direction;

[0033] T2, the distance between the two ends of the second sub-portion of the contact area along the first direction;

[0034] M, the distance between two adjacent collecting electrodes along the first direction;

[0035] L, a distance between the first end and the second end of the bonding portion along the second direction;

[0036] d. The distance between the geometric centers of adjacent bonding portions on the same electrical connection line;

[0037] s, the distance between the geometric center of the bonding portion on an electrical connection line closest to the battery edge and the battery edge;

[0038] P, the length of the battery body along the first direction. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present application. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0040] The terms used herein are only for describing specific embodiments and are not intended to limit the present application. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0041] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.).

[0042] In related technologies, solar cells, such as TOPCon cells or back-contact cells, have few or no grid lines on the cell surface (0BB cells). These cells are typically secured by soldering thin grids to a soldering ribbon, and then applying glue along the ribbon's extension. However, arbitrarily placing glue not only increases glue consumption and costs, but also makes it difficult to ensure a reliable connection between the ribbon and the cell.

[0043] In the process of realizing the concept of this application, it was found that this application is based on discretely arranging the adhesive part on at least one surface of the battery body to fix the electrical connection line on the battery surface. By setting the ratio of the distance between the end of the adhesive part in the second direction and the electrical connection line to the width of the electrical connection line within a certain range, it can not only ensure the strength of the mutual connection between the electrical connection line and the battery cell, but also reduce the cost of using adhesive materials and improve the yield of photovoltaic modules.

[0044] Specifically, according to an embodiment of one aspect of the present application, a photovoltaic assembly is provided. Figure 1 A partial top view of a photovoltaic module according to an embodiment of the present application is shown, wherein the size of the glue point (adhesive portion 4) is for illustration only and does not represent the actual size.

[0045] like Figure 1 As shown, the photovoltaic module includes: a battery body 1, a plurality of collecting electrodes 2, a plurality of electrical connection wires 3 and a plurality of bonding parts 4. The plurality of collecting electrodes 2 are located on at least one surface of the battery body 1. The collecting electrodes 2 (also known as fine grids, collecting grid lines, auxiliary grids, contact grid lines, etc.) are arranged in a first direction (such as Figure 1and arranged in a second direction (as shown in the upper and lower directions) that intersects the first direction. Figure 1 The plurality of electrical connection wires 3 (also known as welding ribbons or interconnecting strips) are disposed on the surface of the cell body 1 and extend along a first direction to connect adjacent cell bodies 1. These wires are used to connect at least two solar cells in series and are suitable for collecting and transmitting current from the current collecting electrodes 2. Optionally, the electrical connection wires 3 are electrically connected to the plurality of current collecting electrodes 2.

[0046] Multiple bonding portions 4 are located on at least one surface of the battery body 1 and are discretely distributed and cover at least a portion of the outer surface of the electrical connection wire 3, suitable for bonding and securing the electrical connection wire 3 to the battery body 1. The bonding portion 4 defines a contact region 41 with the surface of the battery body 1. The contact region 41 has a first end 42 and a second end 43 in the second direction.

[0047] Along the second direction, the distance between the first end 42 or the second end 43 of the bonding portion 4 and the electrical connection wire 3 to which it is bonded is A, and the width of the electrical connection wire 3 along the second direction is X, where A=aX, where 2≤a≤8. According to the embodiments of the present application, by discretely distributing the bonding portions 4 and at least partially covering the electrical connection wire 3, it helps to help improve the connection strength between the electrical connection wire 3 and the battery body 1, thereby improving the yield and reliability of the assembly.

[0048] It should be noted that the adhesive portion 4 can be provided between adjacent current collecting electrodes 2 to help strengthen the connection strength between the electrical connection wire 3 and the battery body 1 and prevent the adhesive portion 4 from contacting the current collecting electrodes 2, which could affect current transmission between the electrical connection wire 3 and the current collecting electrodes 2 and reduce the yield of the photovoltaic module. The adhesive portion 4 can also cover at least one current collecting electrode 2, for example, it can cover both current collecting electrodes. This arrangement helps provide effective bonding strength through the adhesive portion 4.

[0049] Specifically, Figure 2 FIG. 1 shows a cross-sectional schematic diagram of the bonding portion of an embodiment of the present application. Figure 2 As shown, the electrical connection line 3 has a projection on the surface of the battery body 1 in a direction perpendicular to the surface of the battery body 1. Along the second direction, the projection is close to a side boundary of one end of the bonding portion 4, and the distance A between the projection and the endpoint of the one end is.

[0050] The distance A between one end of the bonding portion 4 and the electrical connection line 3 can be understood as the distance between the bonding portion 4 and the electrical connection line 3 in the extending direction (i.e. Figure 2 The first direction in the vertical direction (i.e. Figure 2 The maximum length of a single side in the second direction.

[0051] It can be understood that the first end or the second end of the adhesive portion 4 can be understood as the endpoint of the adhesive portion 4 on the outer contour line of the projection of the battery body 1, which is farthest from the electrical connection line 3. The distance A between the first end or the second end of the adhesive portion and the electrical connection line can be understood as the distance A between the first end or the second end of the adhesive portion and the electrical connection line, obtained by drawing a perpendicular line segment from the endpoint farthest from the electrical connection line 3 in the extension direction of the electrical connection line 3 (which can be understood as the first direction).

[0052] More specifically, the contact region 41 of the adhesive portion 4 includes a first sub-portion 411 and a second sub-portion 412 . Figure 3 Schematic cross-sectional view of the first sub-section and the second sub-section of the embodiment of the present application is shown. Figure 3 As shown, the projection is close to the boundary of the first end 42 of the bonding portion 4, and the distance from the first end 42 is A1. The projection is close to the boundary of the second end 43 of the bonding portion 4, and the distance from the second end 43 is A2.

[0053] It should be noted that the projection shapes of the adhesive portion 4 formed by printing on both sides of the electrical connection line 3 along the second direction may be somewhat asymmetric, for example, Figure 3 As shown, the size or shape of the first sub-section 411 and the second sub-section 412 may differ. In this case, the aforementioned A=aX is satisfied, and the coefficient a is in the range of 2≤a≤8. This can enhance the bonding effect on both sides of the electrical connection line 3, thereby reducing the material usage of the bonding portion 4.

[0054] Optionally, the arrangement of the bonding portion 4 can be as follows Figure 1 As shown, it is partially disposed between adjacent collector electrodes 2; it can also be disposed between every two adjacent collector electrodes 2 as needed, and can also at least partially cover multiple collector electrodes 2 as described above. This application can be adjusted based on the component's requirements for welding strength, and this application does not specifically limit this.

[0055] According to the embodiments of the present application, the photovoltaic module of the present application can be a photovoltaic module composed of bifacial cells, such as an HJT photovoltaic module (a module composed of heterojunction cells), a TOPCon photovoltaic module (a module composed of tunneling oxide passivation contact cells), or a photovoltaic module composed of back contact cells. Furthermore, the photovoltaic module composed of back contact cells can be a traditional IBC photovoltaic module (a module composed of interdigitated back contact cells), or a TBC photovoltaic module (a module composed of TOPCon back contact cells), an HBC photovoltaic module (a module composed of heterojunction back contact cells), or a hybrid photovoltaic module (i.e., wherein the PN passivation is a different passivation material, for example, it can be a combination of polycrystalline silicon passivation and amorphous / microcrystalline passivation).

[0056] The photovoltaic module comprises a cell body 1 , which at least comprises a substrate and a doping layer on the substrate, wherein the substrate is a rectangular or square structure.

[0057] The cell body 1 of the HJT photovoltaic module has a first surface and a second surface disposed opposite each other. The first surface may be the backlight side, and the second surface may be the light-receiving side. The doped layer includes an n-doped region and a p-doped region. The n-doped region is located on the first surface, and the p-doped region is located on the second surface. The n-doped region and the p-doped region can be interchanged as needed, without specific limitation.

[0058] The cell body 1 of the TOPCon photovoltaic module has a first surface and a second surface disposed opposite each other. The first surface may be the backlight side, and the second surface may be the light-receiving side. The doped layer includes an n-doped region and a p-doped region. The n-doped region is located on the first surface, and the p-doped region is located on the second surface. The n-doped region and the p-doped region can be interchanged as needed, without specific limitation.

[0059] The cell body 1 of the IBC photovoltaic module comprises n-doped regions and p-doped regions arranged alternately along a first direction on a substrate to form an interdigitated doping structure. The n-doped regions and p-doped regions are each provided with an alternate electrode structure.

[0060] The cell body 1 of the TBC photovoltaic module comprises a tunneling oxide layer disposed on a substrate, and n-doped and p-doped regions formed from doped polysilicon layers. The TOPCon structure formed by the stacked tunneling oxide layer and doped polysilicon layers offers a longer carrier lifetime and lower surface recombination compared to IBC photovoltaic modules, thereby improving the photovoltaic conversion efficiency of the TBC photovoltaic module.

[0061] The cell body 1 of the aforementioned HBC photovoltaic module comprises an n-doped region and a p-doped region disposed on a substrate to form a heterojunction structure. The n-doped region includes, but is not limited to, microcrystalline silicon or amorphous silicon (to provide electrons), while the p-doped region can also be made of microcrystalline silicon or amorphous silicon (e.g., using boron as a dopant to provide holes). HBC photovoltaic modules help improve carrier lifetime and reduce surface recombination. Furthermore, a transparent conductive oxide layer (TCO) can be provided between the surfaces of the n-doped and p-doped regions and the electrodes. This facilitates carrier collection in the doped regions and also provides a certain degree of anti-reflection.

[0062] The cell body 1 of the hybrid photovoltaic module can adopt a layer structure similar to that of an IBC cell or a TBC cell, and configure a corresponding passivation layer structure thereon, such as a combination of at least two of polycrystalline silicon passivation, amorphous silicon passivation and microcrystalline silicon passivation.

[0063] The main material of the doping layer can be selected from silicon (Si), germanium (Ge), silicon carbide (SiCx ) or gallium arsenide (GaAs) and other semiconductor materials, which can be amorphous, microcrystalline, single crystal, nanocrystalline, or polycrystalline. Donor impurities such as phosphorus (P), arsenic (As), or antimony (Sb) are introduced into the aforementioned semiconductor materials to form an n-doped region. Acceptor impurities such as boron (B), aluminum (Al), or gallium (Ga) are introduced into the aforementioned semiconductor materials to form a p-doped region.

[0064] The first surface of the cell body 1 of the photovoltaic module composed of the aforementioned back-contact cells comprises first and second regions arranged alternately along a first direction, and an isolation region (also called a gap region) located between the first and second regions. The n-doped region of the doped layer is located on the first region, and the p-doped region is located on the second region. The two regions are interchangeable and are not specifically defined here. The isolation region serves to separate the n-doped and p-doped regions at their boundaries to prevent short circuits and also to prevent direct contact between the n-doped and p-doped regions.

[0065] Optionally, the collecting electrode 2 may include a metal (such as Ag, Cu, Al, Ni, Au, Zn, Sn, Pb, silver-coated copper or a combination of the above metals, etc.), a conductive metal oxide (various TCOs, such as ITO, AZO, IWO, etc.), a metal nitride (TiN, etc.), a metal carbide (TiC, etc.), or a metal sulfide, etc., as well as other conductive connecting materials (such as graphene, etc.), or various combinations of the above materials.

[0066] Alternatively, the current collecting electrode 2 may be formed using processes such as printing, physical vapor deposition, and electrodeposition. Furthermore, printing may be, for example, screen printing, inkjet printing, or laser transfer. The following exemplifies the process of preparing the current collecting electrode 2 by screen printing: preparing a metal slurry containing metal powder; using a screen template with a specific pattern to define the position and shape of the current collecting electrode 2; imprinting the metal slurry onto the battery surface through the screen template to form the patterned structure of the current collecting electrode 2; removing the solution from the metal slurry through a heating and drying process, and then performing high-temperature sintering to achieve good contact between the current collecting electrode 2 and the battery body 1.

[0067] Furthermore, setting the ratio of A to X within the above range can enhance the fixing effect on the electrical connection wire 3 while also preventing an increase in the cost of adhesive materials due to an excessively large area covered by the adhesive portion 4. This ensures the connection reliability between the electrical connection wire 3 and the collector electrode 2 while saving costs. If the ratio is too high, the value of A is too large, resulting in an increase in material costs; if the ratio is too low, the value of A is too small, making it difficult to achieve a good fixing effect on the electrical connection wire 3.

[0068] For example, a can be 2, 3, 4, 5, 6, 7 or 8, or a range consisting of any two of the above values.

[0069] In some embodiments, the cells in the photovoltaic module may be busbar-less cells. In other embodiments, the cells in the photovoltaic module may be busbar-equipped cells, where the electrical connection line 3 is connected to the busbar, which is connected to the collector electrode 2 .

[0070] In some embodiments, the photovoltaic module further includes: a connecting electrode (not shown in the figure), which is in direct contact and electrically connected to multiple collecting electrodes 2 of the same polarity and is electrically isolated from collecting electrodes 2 of different polarities. The connecting electrode extends along the first direction or the second direction. The connecting electrode can be a portion on the collecting electrode 2 used for conductive interconnection, or it can be a structure such as a thickened section or a pad on the collecting electrode 2 that is welded to the electrical connection line 3. Of course, an auxiliary welding layer can also be provided between the connecting electrode and the electrical connection line 3. The auxiliary welding layer can be, for example, solder or solder paste, such as solder, which is used to weld the collecting electrode 2 and the electrical connection line 3; it can also be a conductive adhesive layer, such as conductive silver paste, conductive glue, etc., which is used to conductively bond the collecting electrode 2 and the electrical connection line 3.

[0071] Optionally, the electrical connection line 3 may be made of copper, silver, or silver-clad copper.

[0072] Optionally, the electrical connection line 3 and the collecting electrode 2 may be made of metal strips with various cross-sectional shapes, such as circular, triangular, rectangular, flat, elliptical, or rectangular with chamfered corners, etc., which is not particularly limited in this application.

[0073] In some embodiments, the bonding portion 4 is made of a light-curing adhesive or a thermosetting adhesive. The bonding portion 4 has excellent bonding strength, effectively securing the electrical connection wire 3, and also provides good insulation. When the electrical connection wire 3 is made of copper paste, a light-curing adhesive (UV-curing adhesive) can be used to significantly reduce copper oxidation caused by annealing in air. When the electrical connection wire 3 is made of silver-coated copper paste, the silver coating allows for annealing in air with a thermosetting adhesive, mitigating potential oxidation issues with the copper paste and improving the electrical conductivity of the electrical connection wire 3.

[0074] In some embodiments, since the thermosetting adhesive contains a volatile solvent component, it has a certain curing volatility during the heat curing process, resulting in a certain number of pores during the screen printing and heat curing process, and the number of pores is ≥1. Pores may be introduced before and after the curing process and in the subsequent lamination process of forming photovoltaic modules. A certain number of pores will also be introduced when using photocuring adhesive. It should be noted that because the content of volatile solvents in photocuring adhesive is very small, the number of pores is less than that of thermosetting adhesive during screen printing and subsequent lamination using photocuring adhesive, and the fixing effect and insulation performance it brings are relatively more stable.

[0075] Furthermore, the photocurable adhesive is cured by ultraviolet light, and the bonding strength between a single adhesive portion 4 and the electrical connection wire 3 must be greater than 0.4N, thereby ensuring the welding reliability between the electrical connection wire 3 and the collector electrode 2. In a photovoltaic module, an electrical connection wire 3 can be fixed by a single adhesive portion 4 or by two or more adhesive portions 4 as needed.

[0076] In some embodiments, forming the bonding portion 4 on the electrical connection line 3 on the surface of the battery body 1 may include: providing a mesh template having a specific pattern, the template having a plurality of through holes arranged at intervals; placing the mesh template on the surface of the battery body 1 so that the plurality of through holes correspond to the positions of the battery body 1 where the bonding portion 4 is to be applied; and screen printing to place an adhesive material in the plurality of through holes to form an initial bonding portion between the electrical connection line 3 and the surface of the battery body 1. The initial bonding portion is then cured by ultraviolet light or heating to form the bonding portion 4.

[0077] In some embodiments, the plurality of adhesive portions 4 may cover at least a portion of the outer surface of the electrical connection wire 3. It is understood that, for example, the adhesive portion 4 may partially cover the electrical connection wire 3 in the contact area 41, leaving a portion of the electrical connection wire 3 exposed from the top of the adhesive portion 4 in the thickness direction. Alternatively, the adhesive portion 4 may completely cover the outer surface of the contact area 41 of the electrical connection wire 3. Figure 4 shows a cross-sectional view of the bonding portion 4 according to an embodiment of the present application; Figure 5 FIG. 4 shows a cross-sectional view of the bonding portion 4 of another embodiment of the present application. Figure 4 and Figure 5 As shown, the present application does not specifically limit whether the adhesive portion 4 completely covers the outer surface of the contact area 41 , and it only needs to fully fix the electrical connection wire 3 .

[0078] Preferably, the plurality of adhesive portions 4 completely cover the outer surface of the contact area 41 of the electrical connection line 3. This arrangement can further enhance the fixing effect of the electrical connection line 3 and improve the yield rate of the photovoltaic module.

[0079] It should be noted that the initial bonding portion can be formed on the surface of the battery body 1, and then the electrical connection wire 3 can be at least partially embedded in the initial bonding portion before performing the curing operation. Alternatively, the current collecting electrode 2 and the electrical connection wire 3 can be welded to the surface of the battery body 1, and then the initial bonding portion can be formed on at least a portion of the surface of the electrical connection wire 3. Preferably, welding is performed first to complete the preliminary connection between the electrical connection wire 3 and the battery body 1, and then the initial bonding portion is formed and cured to achieve further fixation, thereby enhancing the welding reliability between the electrical connection wire 3 and the current collecting electrode 2.

[0080] The following will describe in detail the specific structural settings for different solar cells.

[0081] Figure 1 This can be a back-contact battery. The collecting electrode 2 includes a first collecting electrode and a second collecting electrode. The first collecting electrode and the second collecting electrode have opposite polarities. The first collecting electrode and the second collecting electrode are both located on a surface of the battery body 1 (for example, the back surface of the battery body 1). It is understood that the first collecting electrode can be located on a p-doped region to extract carriers from the p-doped region; the second collecting electrode can be located on an n-doped region to extract carriers from the n-doped region. Of course, the first collecting electrode and the second collecting electrode can also be interchanged, and this is not specifically limited here. The bonding portion 4 can be located between adjacent first and second collecting electrodes, and the bonding portions 4 located on both sides of a collecting electrode 2 are correspondingly arranged along the first direction. Corresponding arrangement can be understood as, along the first direction, the geometric center of one bonding portion 4 and the geometric center of the adjacent bonding portion 4 are located on a common straight line. Providing the adhesive portion 4 at the aforementioned position and ensuring that the ratio of the distance A between one end of the adhesive portion 4 and the electrical connection wire 3 at least partially covered by the adhesive portion 4 to the width X of the electrical connection wire 3 along the second direction is within the aforementioned range (A=aX, 2≤a≤8) helps to save the cost of the material used in the adhesive portion 4 and improve the bonding yield between the electrical connection wire 3 and the battery body 1.

[0082] Figure 1It can be a bifacial battery or a TOPcon battery, and the collecting electrode 2 includes a first collecting electrode and a second collecting electrode, the first collecting electrode and the second collecting electrode have opposite polarities, and the first collecting electrode and the second collecting electrode are respectively located on the front and back of the battery body 1. For example, the first collecting electrode can be located on the front of the battery body 1 and the second collecting electrode can be located on the back of the battery body 1, or the first collecting electrode can be located on the back of the battery body 1 and the second collecting electrode can be located on the front of the battery body 1, and there is no special limitation here. At least one bonding portion 4 can be located between adjacent collecting electrodes 2 of the same polarity, and the bonding portions 4 located on both sides of a collecting electrode 2 are correspondingly arranged along the first direction. The corresponding arrangement can be understood as that, along the first direction, the geometric center of one bonding portion 4 and the geometric center of the adjacent bonding portion 4 are located on a common straight line. Providing the adhesive portion 4 at the aforementioned position and ensuring that the ratio of the distance A between one end of the adhesive portion 4 and the electrical connection wire 3 covered by the adhesive portion 4 to the width X of the electrical connection wire 3 along the second direction is within the aforementioned range helps to improve the bonding yield between the electrical connection wire 3 and the battery body 1 while saving the material cost of the adhesive portion 4. Figure 6 A partial top view of the bonding portion of an embodiment of the present application is shown. Figure 7 FIG. 1 shows a partial top view of the bonding portion of another embodiment of the present application. Figure 6-7 As shown, the distance between the two ends of the contact area 41 of the adhesive portion 4 along the first direction is T. T can be understood as the maximum width of the adhesive portion 4 along the first direction on either side of the electrical connection line 3 along the second direction, that is, the distance between the two ends of the contact area 41 of the adhesive portion 4 along the first direction on either side of the electrical connection line along the first direction. Wherein, 0.2≤(A:T)≤1. This configuration enables the adhesive portion 4 to effectively secure the electrical connection line 3 to the battery body 1 in both the first and second directions while reducing the amount of adhesive material used. If the ratio of the two is less than 0.2, the two ends in the second direction will have a poorer securing effect on the electrical connection line 3; if the ratio is greater than 1, the two ends in the first direction will have a poorer securing effect on the electrical connection line 3.

[0083] For example, A / T may be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0, or a range between any two of the above values.

[0084] Optionally, 0.3≤(A:T)≤0.7. This configuration can reduce the amount of adhesive material used while strengthening the bonding strength between the electrical connection wire 3 and the battery body 1 through the adhesive portion 4, thereby saving costs.

[0085] In some embodiments, the battery body 1 includes a front side (which may also be a light-facing side) and a back side (which may also be a backlight side). For the adhesive portion 4 disposed on the light-facing side of the battery body 1, 0.2 ≤ (A:T) ≤ 0.5. This arrangement minimizes obstruction of the light-facing side by the adhesive portion 4 while enhancing the connection between the electrical connection wire 3 and the battery body 1, thereby improving light utilization.

[0086] In some embodiments, the bonding portion 4 disposed on the backlight side of the cell body 1 has a ratio of 0.4 ≤ (A:T) ≤ 0.7. This configuration strengthens the connection reliability between the electrical connection wire 3 and the cell body 1, particularly between the electrical connection wire 3 and the current collecting electrode 2, thereby ensuring stable operation of the photovoltaic module.

[0087] In some embodiments, as Figure 1 As shown, the distance between two adjacent collector electrodes 2 is M, which can be understood as the straight-line distance between two adjacent collector electrodes 2 along the first direction. As mentioned above, T can be understood as the maximum width of the bonding portion 4 along the first direction. M and T must satisfy M / T < 1.2. Figure 1 and Figure 6 As shown, adjusting the ratio of the two within the above range is helpful to form a more firm fixation of the electrical connection wire 3, thereby enhancing the connection strength between the electrical connection wire 3 and the battery body 1.

[0088] For example, the ratio between the two can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 or 1.2, or a range consisting of any two of the above values.

[0089] Optionally, M / T < 1. This configuration can increase the contact area between the bonding portion 4 and the battery body 1 and the collector electrode 2 in the contact region 41 while reducing the use of bonding material, thereby making the connection between the electrical connection wire 3 and the battery body 1 tighter and enhancing the bonding strength.

[0090] In some embodiments, along the first direction, the distance M between two collector electrodes 2 adjacent to the bonding portion 4 is greater than or equal to 0.8 mm and less than or equal to 1.2 mm. This configuration helps to better achieve the collection of carriers.

[0091] Optionally, M may be, for example, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm or 1.2 mm, or a range consisting of any two of the above values.

[0092] In some embodiments, the contact area 41 of the adhesive portion 4 has a T of ≥0.5 mm and ≤4 mm at both ends along the first direction. This arrangement ensures that there is sufficient contact area between the contact area 41 of the adhesive portion 4 and the electrical connection wire 3, thereby strengthening the welding reliability between the electrical connection wire 3 and the collector electrode 2 and providing better mechanical strength. When subjected to external force or vibration, the electrical connection wire 3 will not easily fall off from the adhesive portion 4, thereby enhancing the reliability and stability of the entire photovoltaic module. If T is too short, it is difficult to fix the electrical connection wire 3. If T is too long, it not only leads to excessive consumption of material costs, but also affects the flexibility and operability of the electrical connection wire 3 due to excessive coverage of the electrical connection wire 3. For example, when connecting to the next battery cell, when the electrical connection wire 3 needs to be bent, etc., the excessive coverage makes the electrical connection wire 3 relatively rigid, which is not conducive to installation and maintenance.

[0093] Optionally, T may be, for example, 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm or 4 mm, or a range consisting of any two of the above values.

[0094] Furthermore, if the adhesive portion 4 is located on the front (light-facing) side of the battery body 1, T is ≥ 1.5 mm and ≤ 3 mm. This arrangement strengthens the adhesive portion 4's ability to secure the electrical connection wire 3, minimizing the risk of the electrical connection wire 3 becoming detached from the battery body 1, for example, if the battery body 1 warps or bends. Furthermore, reducing the T value of the contact area 41 of the adhesive portion 4 reduces obstruction of the cell and improves photoelectric conversion efficiency.

[0095] Furthermore, if the bonding portion 4 is disposed on the back side (backlight side) of the battery body 1, T is ≥ 1.5 mm and ≤ 2 mm. This configuration can enhance the fixing effect of the bonding portion 4 on the electrical connection wire 3, save adhesive materials, and save costs.

[0096] In some embodiments, the distance between the first end 42 and the second end 43 of the bonding portion 4 along the second direction is L. Figure 3 As shown, L can be understood as A1+X+A2, L≥1mm, and ≤3mm. Such a setting can save the amount of adhesive material and reduce the cost of solar cells while ensuring the welding reliability between the electrical connection line 3 and the battery cell. If the spacing L between the first end 42 and the second end 43 of the bonding portion 4 along the second direction is too wide, it will cause increased costs and may contact the adjacent collecting electrode 2, which will have an adverse effect on the conductive performance. If the spacing L between the first end 42 and the second end 43 of the bonding portion 4 along the second direction is too narrow, the fixing strength of the electrical connection line 3 is weak, which will reduce the welding yield of the photovoltaic module during production and use.

[0097] Optionally, the distance L between the first end 42 and the second end 43 of the adhesive portion 4 along the second direction may be, for example, 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm, or a range consisting of any two of the above values.

[0098] Preferably, the distance L between the first end 42 and the second end 43 of the bonding portion 4 along the second direction is ≥1 mm and ≤2.5 mm. This arrangement can further reduce the consumption of bonding materials while ensuring the bonding effect between the electrical connection wire 3 and the battery cell.

[0099] In some embodiments, the width X of the electrical connection line 3 along the second direction is ≥ 0.1 mm and ≤ 2 mm. Within the above width range, a better welding effect is achieved.

[0100] Optionally, the width X of the electrical connection line 3 along the second direction may be, for example, 0.1 mm, 0.25 mm, 0.5 mm, 0.75 mm, 1 mm, 1.5 mm or 2 mm, or a range consisting of any two of the above values.

[0101] As mentioned above, the electrical connection wire 3 can have a cross-sectional area of ​​any shape. For example, if the cross-sectional area of ​​the electrical connection wire 3 is circular, the width X of the electrical connection wire 3 along the second direction can be understood as its diameter. Preferably, the diameter of the electrical connection wire 3 is ≥0.1mm and ≤0.4mm. More preferably, the diameter of the electrical connection wire 3 is ≥0.2mm and ≤0.3mm. Further preferably, the diameter of the electrical connection wire 3 is ≥0.14mm and ≤0.28mm. This configuration strengthens the connection between the electrical connection wire 3 and the battery cell.

[0102] Taking the cross-sectional area of ​​the electrical connection line 3 as an example, the width X of the square electrical connection line along the second direction is ≥0.5 mm, and X≤2 mm; preferably, the width of the square electrical connection line along the second direction is ≥0.5 mm, and X≤1 mm.

[0103] In some embodiments, the distance between the two ends of the contact area 41 in the first direction is T, and the edge of the contact area has a contour line. The area of ​​the area enclosed by the contour line and the electrical connection line 3 on either side along the second direction is S, and S satisfies: A is consistent with the previous description and will not be repeated here.

[0104] The area S can be understood as the area enclosed by the edge contour of the contact area 41 of the bonding portion 4 on either side of the electrical connection line 3 along the second direction on the surface of the battery body 1 and the boundary of one side of the electrical connection line 3 projected along the direction perpendicular to the battery body 1. The above edge contour can be obtained by image capture or other methods. Setting the area S within the above range can ensure that the bonding portion 4 has a relatively sufficient fixing effect on the electrical connection line 3, thereby improving the yield of the photovoltaic module and avoiding waste of adhesive materials. If the area S is too large, it will cause waste of adhesive materials and may contact the adjacent collector electrode 2, which will have an adverse effect on the conductive performance; if the area S is too small, it will not play a good fixing role, and the electrical connection line 3 may fall off, reducing the reliability of the connection between the electrical connection line 3 and the battery cell.

[0105] In some embodiments, as Figure 3 As shown, contact region 41 has a first sub-portion 411 and a second sub-portion 412 on either side of electrical connection line 3. First sub-portion 411 has a first end 42, and second sub-portion 412 has a second end 43. Along the second direction, the distance between first end 42 and electrical connection line 3 is A1, and the distance between second end 43 and electrical connection line 3 is A2. The distance between the two ends of first sub-portion 411 of contact region 41 along the first direction is T1, and the distance between the two ends of second sub-portion 412 of contact region 41 along the first direction is T2.

[0106] The first sub-portion 411 has a first contour line, and the area enclosed by the first contour line and the electrical connection line 3 is S1. The second sub-portion 412 has a second contour line, and the area enclosed by the second contour line and the electrical connection line 3 is S2. It is understandable that Figure 3 As shown, the area of ​​the first sub-portion 411 and the second sub-portion 412 can be the same or different. During the screen printing process, due to the influence of forces, the shape and area of ​​the areas on both sides of the electrical connection line 3 may become asymmetric. Therefore, the area of ​​the first sub-portion 411 and the area of ​​the second sub-portion 412 may be different. If they are different, the area of ​​the areas on both sides must meet the aforementioned range to achieve a good fixation effect on the electrical connection line 3.

[0107] It should be noted that A1=a1X, and satisfies 2≤a1≤8. A2=a2X, and satisfies 2≤a2≤8.

[0108] In some embodiments, the projection of the bonding portion 4 on the surface of the battery body 1 is a rhombus, a rhombus-like shape, an ellipse, or a ellipse-like shape; or the projection of the bonding portion 4 on the surface of the battery body 1 on one side of the electrical connection line 3 along the second direction is a parabola-like shape or a cosine-like shape. The morphology of the bonding portion 4 may be close to a rhombus, a rhombus-like shape, or close to an ellipse, or a ellipse-like shape.

[0109] In some embodiments, the ratio A1:A2 is 3:7 to 7:3. This arrangement ensures a relatively balanced area S1 and S2 on either side of the electrical connection wire 3, resulting in a more consistent tension on both sides securing the electrical connection wire 3, further strengthening the bond between the electrical connection wire 3 and the cell. If the ratio is too large, the distance between the first end 42 and the electrical connection wire 3 will be too long, making it easy for the electrical connection wire 3 to lift at the second end 43, leading to poor welding. If the ratio is too small, the distance between the second end 43 and the electrical connection wire 3 will be too long, making it easy for the electrical connection wire 3 to lift at the first end 42, leading to poor welding, and affecting the long-term stability of the module.

[0110] Optionally, A1:A2 can be, for example, 3:7, 4:6, 1:1, 6:4 or 7:3.

[0111] In some embodiments, the distance s between the geometric center of the bonding portion 4 located on an electrical connection line closest to the battery edge and the battery edge is, Figure 8 FIG. 1 shows a partial top view of a photovoltaic module near an edge of an embodiment of the present application. Figure 8 As shown, s≥4mm and ≤24mm. This setting can ensure the connection effect between the electrical connection wire 3 and the battery cell, avoid bending, warping and other phenomena of the electrical connection wire 3 at the edge of the battery, and improve the yield of the component. If s is too large, the electrical connection wire 3 may warp at the edge, resulting in poor contact between the battery cells when connected in series. If s is too small, there are more restrictions on the electrical connection wire 3, making the electrical connection wire 3 fixed more rigidly, making it more difficult to form a certain degree of bending, and having a greater restriction on the position between the interconnected battery cells.

[0112] Optionally, s can be, for example, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm or 24 mm, or a range between any two of the above values.

[0113] In some embodiments, the distance between the geometric centers of adjacent bonding portions 4 on the same electrical connection line 3 is d, and d≤16 mm. Figure 8As shown, if d is greater than the aforementioned range, the securing effect on the electrical connection wire 3 is weak, and there is a risk of desoldering between the electrical connection wire 3 and the current collecting electrode 2. It should be noted that the smaller the range of d, the better. If d is too small, the number of bonding parts 4 will increase, the cost of the bonding material will increase, and the photoelectric conversion efficiency of the component will be adversely affected. For example, due to the limitations of the screen printing process, d needs to be greater than 0.1 mm.

[0114] Optionally, d can be, for example, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm or 16 mm, or a range between any two of the above values.

[0115] In some embodiments, the length of a battery body 1 along the first direction is P, and the number of adhesive portions 4 located on the electrical connection wire 3, N, is ≥ (P - 2s) / 16 + 1. Since d needs to be below 16 mm to effectively enhance the weld between the electrical connection wire 3 and the cell, setting N within the above range effectively avoids the risk of reliability failure during high- and low-temperature cycling testing of the module. It should be noted that during high- and low-temperature cycling testing, the minimum tensile force of a single adhesive point must be ≥ 0.4 N to improve the connection reliability between the electrical connection wire 3 and the current collecting electrode 2.

[0116] In some embodiments, the thickness of the bonding portion 4 may be greater than the thickness of the electrical connection line 3 in a direction perpendicular to the surface of the battery body 1. Figure 4 As shown, such an arrangement can form a better covering effect on the electrical connection wire 3, especially during the high and low temperature cycle process, strengthen the welding effect between the electrical connection wire 3 and the collecting electrode 2, and improve the component yield.

[0117] In some embodiments, the thickness of the bonding portion 4 is smaller than the thickness of the electrical connection line 3 in a direction perpendicular to the surface of the battery body 1. Figure 5 As shown, with this arrangement, during the lamination process, the electrical connection wires are in direct contact with the adhesive film, heat conduction is uniform, and the lamination effect is good.

[0118] It should be noted that, unless otherwise specified, “thickness” generally refers to the dimension in a direction perpendicular to the surface of the battery body 1 .

[0119] In some embodiments, solar cells are connected in series to form a solar cell string, and a packaging structure surrounds the periphery of the solar cell string.

[0120] In some embodiments, the encapsulation structure may include a backsheet, an encapsulation film, and a glass panel to enhance the stability of the solar cell string. The glass panel is located on the front of the solar cell string, while the backsheet is located on the back of the solar cell string, both providing protection. The adhesive film, which acts as a bonding agent between the solar cell string, the glass panel, and the backsheet, must be made of a transparent material.

[0121] In a photovoltaic module, the polarity of the electrical connection line of the adjacent previous solar cell is opposite to the polarity of the electrical connection line of the connected next solar cell to achieve current transmission.

[0122] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above is only a specific embodiment of this application and is not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A photovoltaic module comprising: Battery body; a plurality of current collecting electrodes, located on at least one surface of the battery body; A plurality of collecting electrodes are arranged at intervals in a first direction and extend along a second direction intersecting the first direction; a plurality of electrical connection lines extending along a first direction and connecting adjacent battery bodies, wherein the electrical connection lines are electrically connected to the plurality of current collecting electrodes; a plurality of bonding portions, located on the at least one surface of the battery body, bonding the electrical connection wires to the battery body, the bonding portions having contact areas with the surface of the battery body; wherein the contact area has a first end and a second end in the second direction; Along the second direction, a distance between the first end or the second end of the adhesive portion and the electrical connection line is A, and a width of the electrical connection line along the second direction is X, where A=aX, 2≤a≤8.

2. The photovoltaic module according to claim 1, wherein: The contact area of ​​the adhesive portion is on either side of the electrical connection line along the second direction, and the distance between the two ends along the first direction is T; Among them, 0.2≤(A:T)≤1; preferably, 0.3≤(A:T)≤0.

7.

3. The photovoltaic module according to claim 1, wherein: The distance between the two ends of the contact area of ​​the bonding portion along the first direction is T, and the distance between two adjacent collecting electrodes is M, then, M / T<1.2; preferably, M / T<1.

4. The photovoltaic module according to claim 1, wherein: The distance between the two ends of the contact area of ​​the adhesive portion along the first direction is T, T ≥ 0.5 mm and T ≤ 4 mm; Preferably, T≥1.5mm and T≤3mm; preferably, T≥1mm and T≤2mm.

5. The photovoltaic module according to claim 1, wherein: A distance between the first end and the second end of the adhesive portion along the second direction is L, wherein L is ≥ 1 mm and L is ≤ 3 mm; preferably, L is ≥ 1 mm and L is ≤ 2.5 mm. The photovoltaic module according to claim 1 , wherein: The width of the electrical connection line along the second direction is X ≥ 0.1 mm and X ≤ 2 mm; Preferably, for a circular electrical connection wire, X≥0.1 mm and X≤0.4 mm; more preferably, for a circular electrical connection wire, X≥0.2 mm and X≤0.3 mm; Preferably, for a square electrical connection wire, X≥0.5 mm and X≤2 mm; more preferably, for a square electrical connection wire, X≥0.5 mm and X≤1 mm.

7. The photovoltaic module according to any one of claims 1 to 6, wherein: The distance between the two ends of the contact area in the first direction is T; the edge of the contact area has a contour line, and the area enclosed by the contour line and either side of the electrical connection line is S; wherein, .

8. The photovoltaic module according to claim 7, wherein: The contact area has a first sub-portion and a second sub-portion on both sides of the electrical connection line, the first sub-portion has the first end, and the second sub-portion has the second end; Along the second direction, the distance between the first end and the electrical connection line is A1, and the distance between the second end and the electrical connection line is A2; The distance between the two ends of the first sub-portion of the contact area along the first direction is T1, and the distance between the two ends of the second sub-portion of the contact area along the first direction is T2; wherein, The first sub-portion has a first contour line, and the area enclosed by the first contour line and the electrical connection line is S1 and / or The second sub-portion has a second contour line, and the area of ​​the region enclosed by the second contour line and the electrical connection line is S2. .

9. The photovoltaic module according to claim 8, wherein: A1:A2 is 3:7~7:

3.

10. The photovoltaic module according to claim 2, wherein: The projection of the bonding portion on the surface of the battery body is any one of a rhombus or a rhombus-like shape, an ellipse or a ellipse-like shape; Alternatively, a projection profile of the adhesive portion on the surface of the battery body on one side of the electrical connection line along the second direction is in the shape of a parabola or a cosine curve.

11. The photovoltaic module according to any one of claims 1 to 10, wherein: The bonding portion has pores, and the number of the pores is ≥1; and / or, The bonding portion adopts light-curing glue or thermosetting glue.

12. The photovoltaic module according to any one of claims 1 to 10, wherein: The collecting electrode includes a first collecting electrode and a second collecting electrode, wherein the first collecting electrode and the second collecting electrode have opposite polarities. Wherein, the first collecting electrode and the second collecting electrode are located on the same surface of the battery body; Alternatively, the first collecting electrode is located on the front side of the battery body, and the second collecting electrode is located on the back side of the battery body.

13. The photovoltaic module according to any one of claims 1 to 12, wherein: The distance between the geometric center of the bonding portion on the electrical connection line closest to the edge of the battery and the edge of the battery is s, and s is ≥4 mm and ≤24 mm.

14. The photovoltaic module according to claim 13, wherein: The distance between the geometric centers of adjacent bonding portions on the same electrical connection line is d, and d≤16 mm.

15. The photovoltaic module according to claim 14, wherein: A length of the battery body along the first direction is P, and the number of bonding portions located on the electrical connection line is N≥(P-2s) / 16+1.

16. The photovoltaic module according to any one of claims 1 to 15, wherein: Also includes: a connecting electrode, directly contacting and electrically connected to the plurality of collecting electrodes of the same polarity, and electrically isolated from the collecting electrodes of different polarities; The connecting electrode extends along the first direction.

17. The photovoltaic module according to claim 2, wherein: The battery body includes a light-facing surface and a backlight surface; For the bonding portion provided on the light-facing surface of the battery body, 0.2≤(A:T)≤0.5; and / or For the bonding portion disposed on the backlight surface of the battery body, 0.4≤(A:T)≤0.7.

Images