Photovoltaic module

Abstract

The invention provides a photovoltaic module, and the photovoltaic module comprises a battery piece which is provided with a first surface and a second surface which are opposite to each other; the plurality of first current collection electrodes are located on the first surface, extend in the second direction and are arranged in parallel at intervals in the first direction; the second current collection electrodes are located on the second surface, extend in the second direction and are arranged in parallel at intervals in the first direction, and the first direction intersects with the second direction; the plurality of electric connecting wires extend along the first direction and are connected with two adjacent battery pieces; the first bonding part and the second bonding part are used for bonding the electric connecting wire and the battery piece; the first bonding parts and the second bonding parts are located on the first surface and the second surface of the battery piece respectively, and at least one first bonding part and the first surface have a first contact area; the at least one second bonding part and the second surface have a second contact area; a size of the first contact region is different from a size of the second contact region.

Description

Technical Field

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

[0002] With the development and widespread application of solar cell technology, photovoltaic power generation has become one of the most competitive energy forms in the future. Solar cells convert light energy into electrical energy through the photoelectric effect or photochemical effect. Based on different cell structures, solar cells can be divided into various types, such as emitter and rear passivated (PERC) cells, tunnel oxide passivated contact (TOPCon) cells, and heterojunction with intrinsic thin-layer (HJT) cells.

[0003] Photovoltaic modules are formed by encapsulating multiple solar cells connected in series or parallel, and then converting light energy into electrical energy through the photoelectric effect or photochemical effect. In traditional photovoltaic module designs, the placement of adhesive dots does not take into account the differences in carrier collection and efficiency in different areas of the solar cells, which limits the improvement of module performance. Summary of the Invention

[0004] In view of this, in order to at least partially solve the aforementioned technical problems, this application provides a photovoltaic module.

[0005] According to one embodiment of this application, a photovoltaic module is provided, including multiple cell strings. Each cell string includes: a cell having opposing first and second surfaces; multiple first current collectors located on the first surface, extending along a second direction and arranged in parallel at intervals along the first direction; multiple second current collectors located on the second surface, the multiple first and second current collectors extending along the second direction and arranged in parallel at intervals along the first direction, the first and second directions intersecting; multiple electrical connection lines extending along the first direction and connecting adjacent cells, the electrical connection lines being electrically connected to the multiple first or multiple second current collectors respectively; at least one first adhesive portion and at least one second adhesive portion, the at least one first adhesive portion and at least one second adhesive portion bonding the electrical connection lines and the cell; the first adhesive portion is located on the first surface of the cell, and the first adhesive portion has a first contact area with the surface of the cell; the second adhesive portion is located on the second surface of the cell, and the second adhesive portion has a second contact area with the surface of the cell; wherein the size of the first contact area is different from the size of the second contact area.

[0006] According to the photovoltaic module provided in the above embodiments of this application, by differentiating the size of the bonding portion of the two opposing surfaces in the cell string of the photovoltaic module, a differentiated layout can be made according to the different surface of the cell's requirements for incident light collection, thereby improving the power generation of the module. Attached Figure Description

[0007] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments of this application with reference to the accompanying drawings.

[0008] Figure 1 A top view of the surface of a photovoltaic module according to an embodiment of this application is shown;

[0009] Figure 2 A partial top view of the first surface of a photovoltaic module according to an embodiment of this application is shown;

[0010] Figure 3a A partially enlarged view of the first adhesive portion according to an embodiment of this application is shown;

[0011] Figure 3b A partially enlarged view of the second adhesive portion according to an embodiment of this application is shown;

[0012] Figure 4 A cross-sectional schematic diagram of the first adhesive portion according to an embodiment of this application is shown;

[0013] Figure 5 A distribution diagram of the first adhesive portion and the first current collector electrode according to an embodiment of this application is shown;

[0014] Figure 6 A partial top view of a photovoltaic module near the edge of an embodiment of this application is shown;

[0015] Figure 7a A partial top view of the edge of a battery cell according to an embodiment of this application is shown;

[0016] Figure 7b A partial top view of the edge of a battery cell according to another embodiment of this application is shown.

[0017] The meanings of the reference numerals in the above figures are as follows:

[0018] 1. Battery cells;

[0019] 2. Collector electrode;

[0020] 3. Electrical connection wires;

[0021] 4. First adhesive part;

[0022] 41 - First contact area;

[0023] 5. Second adhesive part;

[0024] 51 - Second contact area;

[0025] 6-Bus electrode;

[0026] 7. End connection points;

[0027] 8. Extended electrode. Detailed Implementation

[0028] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of this application.

[0029] In this application, the relative position between two components (e.g., a membrane or region), as referred to by terms such as "above," "on," or "above," can mean that the two components are in direct contact or that they are not in direct contact. Similarly, the relative position between two components, as referred to by terms such as "below," "under," or "below," can mean that the two components are in direct contact or that they are not in direct contact. For example, when one component (e.g., a membrane or region) is referred to as "on another component," it can be directly on the other component, or there may be other components between them. On the other hand, when a component is referred to as "directly on another component," there are no components between them. Furthermore, when one component is referred to as "on another component," the two components have a vertical relationship in the planar view, and this component can be above or below the other component, thus this vertical relationship depends on the orientation of the device.

[0030] Solar cells, as the core component of photovoltaic modules, significantly impact power generation due to factors such as cell efficiency and light-receiving area. Simultaneously, welding performance affects the module's carrier collection efficiency and power generation performance. In related technologies, solar cells, such as TOPCon or HJT cells, have few or no main grid lines on their surface (OBB cells). These cells are typically fixed by welding fine grids to solder ribbons and then applying adhesive along the ribbon's extension direction. However, arbitrarily setting the adhesive application location not only increases adhesive consumption and costs but may also cause shading, negatively impacting the module's current collection.

[0031] In realizing the concept of this application, it was discovered that this application is based on the differentiated design of the size of the bonding part on different surfaces of the battery string, and can be set differently according to the light incident requirements of different surfaces, so that the component has a good incident light collection effect.

[0032] In particular, for photovoltaic modules composed of bifacial solar cells, such differentiated settings during use help to make differentiated layouts based on the needs of incident light collection and stress conditions at different locations of the solar cells, thereby improving module performance.

[0033] According to the photovoltaic module provided in this application, there are multiple cell strings, and each cell string includes at least one solar cell. The solar cell in this application can be a bifacial cell, such as an HJT cell (heterojunction cell) or a TOPCon cell (tunneling oxide passivation contact cell).

[0034] The aforementioned battery includes a battery body, which at least includes a substrate and a doped layer on the substrate. The substrate has a rectangular or square structure and may have four corners, which may or may not include chamfers. When the corners include chamfers, the chamfers may be as follows: Figure 1 The diagram shown can be composed of curves (arcs), or it can be composed of sloping straight lines. Figure 1 The example shown only illustrates the corners and does not imply a particular limitation on the shape of the corners. It is understood that the substrate can be a rectangle with at least one corner having a chamfer or a square with at least one corner having a chamfer, which is not the focus of this application and will not be described in detail here.

[0035] The aforementioned HJT battery body has a first surface and a second surface arranged opposite to each other. The first surface can be a light-receiving surface, and the second surface can be a backlighting surface. The doped layer includes n-doped regions and p-doped regions. The p-doped regions are located on the first surface, and the n-doped regions are located on the second surface. The two can also be interchanged as needed, without particular limitation here.

[0036] The aforementioned TOPCon battery body has a first surface and a second surface arranged opposite to each other. The first surface can be a light-receiving surface, and the second surface can be a backlighting surface. The doped layer includes n-doped regions and p-doped regions. The p-doped regions are located on the first surface, and the n-doped regions are located within the second surface. The two can also be interchanged as needed, without particular limitation here.

[0037] The materials used in the aforementioned n-doped and p-doped regions can each independently include one or more semiconductor materials such as monocrystalline silicon, amorphous silicon, polycrystalline silicon, or microcrystalline silicon. n-type doping is achieved by introducing donor impurities, such as group VA elements like phosphorus (P), arsenic (As), or antimony (Sb), into the aforementioned semiconductor materials; p-type doping is achieved by introducing acceptor impurities, such as group IIIA elements like boron (B), aluminum (Al), or gallium (Ga), into the aforementioned semiconductor materials.

[0038] Photovoltaic modules based on any of the above embodiments Figure 1 A top view of the surface of a photovoltaic module according to an embodiment of this application is shown; Figure 2A partial top view of the first surface of a photovoltaic module according to an embodiment of this application is shown; Figure 3a A partially enlarged view of the first adhesive portion according to an embodiment of this application is shown; Figure 3b A partially enlarged view of the second adhesive portion according to an embodiment of this application is shown. Figure 1 or Figure 2 The surface in the figure can be any surface of the component. The dimensions of the adhesive dots (first adhesive part 4 or second adhesive part 5) in the above figures are for illustrative purposes only and do not represent actual dimensions. Figures 1-3b As shown, the photovoltaic module of this application includes multiple cell strings, each cell string including: a cell 1, multiple current collectors 2 (a first current collector and multiple second current collectors), multiple electrical connection wires 3, at least one first adhesive portion 4 and at least one second adhesive portion 5.

[0039] The solar cell 1 has a first surface and a second surface. The material of the solar cell 1 can be an n-type, p-type, or intrinsic crystalline silicon substrate, such as a semiconductor material selected from monocrystalline silicon, polycrystalline silicon, and microcrystalline silicon. It can also be an n-type or p-type monocrystalline silicon substrate. The conversion efficiency of solar cells based on monocrystalline silicon substrates is higher than that of other types, such as polycrystalline silicon solar cells. An n-type crystalline silicon substrate is obtained by introducing donor impurities such as group VA elements such as phosphorus (P), arsenic (As), or antimony (Sb) into these semiconductor materials, or a p-type crystalline silicon substrate is obtained by introducing acceptor impurities such as group IIIA elements such as boron (B), aluminum (Al), or gallium (Ga).

[0040] Schematic, the first surface of the battery cell 1 in this application can be the front side of the battery, serving as the primary light-receiving surface; the second surface of the battery cell 1 can be the back side of the battery, serving as the secondary light-receiving surface.

[0041] Multiple collector electrodes 2 (first collector electrode and multiple second collector electrodes) (also called fine grid, collector grid line, sub-grid, etc.), the multiple first collector electrodes and multiple second collector electrodes are all along the second direction (e.g. Figure 1 Extending in the left-right direction (as shown). The first collector electrode extends in the first direction (as shown in the left-right direction). Figure 1 Multiple second current collectors are arranged parallel to each other along the first direction (as shown in the vertical direction) on the first surface of the solar cell 1. These first current collectors are used to collect the current generated on the first surface of the solar cell 1. Multiple second current collectors are arranged parallel to each other along the first direction, intersecting the second direction (e.g., perpendicularly). These second current collectors are used to collect the current generated on the second surface of the solar cell 1. Multiple electrical connecting lines 3 (also called solder ribbons or interconnecting strips) extend along the first direction and connect adjacent solar cells 1, connecting at least two solar cells in series. The electrical connecting lines 3 are suitable for collecting and transmitting current from the current collectors 2.

[0042] For example, the electrical connection line 3 has two ends: one end electrically connects to multiple first current collectors of a single solar cell 1, and the other end electrically connects to multiple second current collectors of an adjacent solar cell 1. That is, the electrical connection line 3 electrically connects multiple current collectors on a single solar cell.

[0043] For the battery string, there are also some electrical connection wires 3 used to connect the beginning and end of the string to the bus bar. These electrical connection wires 3 are only connected to the beginning battery cell 1 or the end battery cell 1, that is, they are only directly connected to one battery cell 1, and not directly connected to two adjacent battery cells 1.

[0044] It is understood that the aforementioned "multiple first collector electrodes" can refer to some or all of the first collector electrodes. Unless otherwise specified, the term "multiple first collector electrodes" in the following text refers to the aforementioned meaning. The aforementioned "first collector electrode" generally refers to an electrode that extends continuously or discontinuously in a first direction. The aforementioned "multiple second collector electrodes" are similar to "multiple first collector electrodes" and will not be elaborated further.

[0045] At least one first adhesive portion 4 and at least one second adhesive portion 5 are bonded to and secure the electrical connection wire 3 to the battery cell 1. The first adhesive portion 4 is located on the first surface of the battery cell 1, and has a first contact area 41 with the surface of the battery cell 1. The second adhesive portion 5 is located on the second surface of the battery cell 1, and has a second contact area 51 with the surface of the battery cell 1. The dimensions of the first contact area 41 and the second contact area 51 are different.

[0046] It should be noted that the term "size" can be understood as the distance between the two ends of the contact area (first contact area 41 and second contact area 51) in the first direction being different; it can also be the distance between the two ends of the contact area in the second direction being different; or it can be the area enclosed by the edge contour lines of the contact area being different. Unless otherwise specified, "size" as used below refers to the foregoing meaning.

[0047] Furthermore, different contact area sizes can be understood as different distances between the two ends of the contact area in the first direction, different distances between the two ends in the second direction, or different areas enclosed by the edge contour lines, at least one of these three cases being different.

[0048] Furthermore, "at least one difference" can be understood as a difference in one of the aforementioned three situations, or it can be a difference in two of the aforementioned three situations, or a difference in all three situations. This application does not make any special limitation in this regard.

[0049] It is understood that the aforementioned "at least one first adhesive part 4" can be one first adhesive part or multiple first adhesive parts. In the case of multiple first adhesive parts, they can be some or all of the first adhesive parts. Unless otherwise specified, "at least one first adhesive part 4" in the following text refers to the foregoing meaning. The aforementioned "at least one second adhesive part 5" is similar to "at least one first adhesive part 4" and will not be repeated.

[0050] It should be noted that the first adhesive portion 4 can be disposed between adjacent first current collector electrodes, which helps to strengthen the connection strength between the electrical connection line 3 and the solar cell 1, and prevents the first adhesive portion 4 from touching the first current collector electrode, thus avoiding interference with current transmission between the electrical connection line 3 and the first current collector electrode and resulting in a lower yield of the photovoltaic module. The first adhesive portion 4 can also cover at least one first current collector electrode, for example, it can cover two first current collector electrodes. This arrangement helps to provide effective adhesive strength through the first adhesive portion 4. The second adhesive portion 5 can be similar to the first adhesive portion 4, and will not be described in detail here.

[0051] According to embodiments of this application, by setting the size difference of the adhesive portion on the two surfaces of the battery cell 1, it is helpful to relieve stress and reduce the risk of microcracks or cell cracks.

[0052] Optionally, the plurality of first collector electrodes and the plurality of second collector electrodes may each independently comprise metals (e.g., Ag, Cu, Al, Ni, Au, Zn, Sn, Pb, silver-plated copper, or combinations thereof), conductive metal oxides (various TCOs, such as ITO, AZO, IWO, etc.), metal nitrides (TiN, etc.), metal carbides (TiC, etc.), or metal sulfides, as well as other conductive connecting materials (e.g., graphene, etc.), or various combinations thereof.

[0053] Optionally, the first and second current collector electrodes can be formed using processes such as printing, physical vapor deposition, and electrodeposition. Further, printing can be, for example, screen printing, inkjet printing, or laser transfer. The following exemplarily illustrates the process of preparing the current collector electrode 2 (first and / or second current collector electrode) by screen printing: preparing a metal paste containing metal powder; using a screen template with a specific pattern to define the position and shape of the current collector electrode 2; pressing the metal paste onto the battery surface through the screen template to form a patterned structure of the current collector electrode 2; removing the solvent from the metal paste by heating and drying, followed by high-temperature sintering to achieve good contact between the current collector electrode 2 and the battery cell 1.

[0054] In some embodiments, an auxiliary welding layer may be provided between the electrical connection line 3 and the current collector 2. This layer may be solder, solder paste, or solder, for example, to weld the current collector 2 to the electrical connection line 3. Alternatively, it may be a conductive bonding layer, such as conductive silver paste or conductive adhesive, for conductive bonding between the current collector 2 and the electrical connection line 3.

[0055] Optionally, the electrical connection wire 3 can be made of copper, silver, or silver-clad copper.

[0056] Optionally, the electrical connection line 3 and the current collector 2 can be metal strips with various cross-sectional shapes, such as circular, triangular, rectangular, flat, elliptical or chamfered rectangles, etc., and this application does not make any particular limitation in this regard.

[0057] In some embodiments, the adhesive portions (first adhesive portion 4 and / or second adhesive portion 5) can be made of UV-curable adhesive. The adhesive portions have excellent adhesion, effectively securing the electrical connection wire 3, and also possess good insulation properties. The UV-curable adhesive is cured by ultraviolet light, and the adhesion strength between each adhesive portion and the electrical connection wire 3 must be at least 0.4 N. This ensures reliable welding between the electrical connection wire 3 and the current collector electrode 2. In photovoltaic modules, one or more adhesive portions can be used to secure a single electrical connection wire 3, as needed.

[0058] In some embodiments, forming an adhesive portion on the electrical connection lines 3 on the surface of the battery cell 1 may include: providing a mesh template with a specific pattern and having a plurality of through holes spaced apart; placing the mesh template on the surface of the battery cell 1 such that the plurality of through holes correspond to the positions on the battery cell 1 where the adhesive portion needs to be applied; performing screen printing to deposit adhesive material within the plurality of through holes to form an initial adhesive portion on the electrical connection lines 3 and the surface of the battery cell 1; and then curing the initial adhesive portion using ultraviolet light to form the adhesive portion.

[0059] In some embodiments, the adhesive portion may cover at least a portion of the outer surface of the electrical connection wire 3. For example, the adhesive portion may partially cover the electrical connection wire 3, such that a portion of the electrical connection wire 3 is exposed from the top position in the thickness direction of the adhesive portion. Alternatively, the adhesive portion may cover the top of the electrical connection wire 3.

[0060] Preferably, the adhesive portion covers the top of the electrical connection wire 3. This arrangement further enhances the fixing effect on the electrical connection wire 3 and improves the yield of the photovoltaic module.

[0061] It should be noted that an initial adhesive portion can be formed on the surface of the battery cell 1 first, and then the electrical connection wire 3 can be at least partially embedded into the initial adhesive portion before curing. Alternatively, the current collector electrode 2 can be welded to the electrical connection wire 3 on the surface of the battery cell 1 first, and then an initial adhesive 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 initial connection between the electrical connection wire 3 and the battery cell 1, and then the initial adhesive portion is formed and cured to achieve further fixation, thereby enhancing the welding reliability between the electrical connection wire 3 and the current collector electrode 2.

[0062] It is understandable that the thickness of the electrical connection lines 3 on the first and second surfaces can be the same, and the degree to which the first adhesive portion 4 and the second adhesive portion 5 cover the electrical connection lines 3 is not significantly different. In other words, the dimensional difference between the first adhesive portion 4 and the second adhesive portion 5 in the thickness direction is small and can be ignored. The size of the first contact area 41 is relatively larger. That is, when the difference in the thickness direction is small, the surface of the first adhesive portion 4 has a relatively gentler slope. This can be understood as the angle formed between the slope of the first adhesive portion 4 and the first surface of the battery cell 1 being smaller than the angle formed between the slope of the second adhesive portion 5 and the second surface of the battery cell 1. Reducing the total internal reflection of incident light at the interface and allowing more incident light to enter the battery cell 1 can improve the transmittance of incident light and enhance light utilization.

[0063] In some implementations, the photovoltaic module also includes an encapsulating film layer that covers the cell string. This film layer is located between the cell string and the glass panel or backsheet to protect the cell string.

[0064] The adhesive film layer bonds and secures the battery string to the glass panel. To reduce the adverse effects on light incidence, the adhesive film layer can be made of a transparent material.

[0065] In some embodiments, the refractive index of the first adhesive portion 4 is greater than that of the adhesive film layer, and the size of the first contact area 41 is greater than that of the second contact area 51. In particular, when the first surface is the front side, the incident light collection effect on the front side of the solar cell is further improved, thereby increasing the power generation of the module.

[0066] On the other hand, the front of the component is subjected to greater impact than the back. The size of the first bonding part 4 is larger than that of the second bonding part 5. The gentler slope can better buffer the impact of the adhesive film flow during the lamination process and reduce the stress on the surface of the cell, reduce microcracks and welding failures, improve yield, and reduce manufacturing costs.

[0067] It should be noted that, unless otherwise specified, “thickness” generally refers to the dimension along the direction perpendicular to the surface of cell 1.

[0068] In some embodiments, the solar cells in the photovoltaic module can be grid-less cells (OBB). In other embodiments, the solar cells in the photovoltaic module can be grid-connected cells, with electrical connection line 3 connected to the grid (busbar electrode) and the grid (busbar electrode) connected to the collector electrode.

[0069] Solar cells can include uncut solar cells or cut solar cells.

[0070] Among them, non-cut solar cells refer to solar cells where silicon wafers are cut to the required size before solar cell manufacturing.

[0071] Cutting solar cells refers to the process of cutting a whole solar cell into P individual cells, where 2 ≤ P ≤ 8. It can be understood that this application involves cutting a large silicon wafer solar cell (e.g., (90mm~300mm) × (156mm~300mm), where the whole cell can be a square or rectangular wafer) into 2~8 individual solar cells.

[0072] Optionally, P can be, for example, 2, 3, 4, 5, 6, 7 or 8, and this application does not impose any particular limitation on it.

[0073] In some embodiments, the length of the battery cell along the second direction is 156-220 mm, and the width along the first direction is 45-150 mm.

[0074] Optionally, the length of the solar cell along the second direction may be, for example, 156mm, 180mm, 182mm, 183mm, 185mm, 190mm, 205mm, 210mm, 215mm or 220mm, or a range consisting of any two of the above values.

[0075] Optionally, when P=2, the length of the solar cell along the second direction is 180~220mm, and the width along the first direction is 75~115mm. Optionally, the width of the solar cell along the first direction can be, for example, 75mm, 80mm, 85mm, 90mm, 95mm, 96mm, 97mm, 98mm, 99mm, 100mm, 101mm, 102mm, 103mm, 104mm, 105mm, 106mm, 107mm, 108mm, 109mm, 110mm, 111mm, 112mm, 113mm, 114mm, or 115mm, or a range consisting of any two of the above values.

[0076] Preferably, when P=4, the length of the solar cell along the second direction is 180~220mm, and the width along the first direction is 45~60mm. This length and width setting achieves a balance between module power, output current, and overall performance, resulting in better performance. Optionally, the width of the solar cell along the first direction can be, for example, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, 51mm, 52mm, 53mm, 54mm, 55mm, 56mm, 57mm, 58mm, 59mm, or 60mm, or a range consisting of any two of the above values.

[0077] Preferably, the length of the solar cell along the second direction is 182~184mm or 190~220mm, which can make reasonable use of the silicon wafer, reduce raw material waste, be compatible with existing production lines, and avoid large-scale equipment modification. More preferably, it is 191~215mm.

[0078] In a module composed of bifacial cells, the electrical connection line 3 of the adjacent first cell has the opposite polarity to the electrical connection line 3 of the connected second cell. That is, the electrical connection line 3 on the first surface of the first cell is connected to the electrical connection line 3 on the second surface of the second cell. Based on the need to bend the electrical connection line 3 at the edge of the cell to a certain extent, the size of the first contact area 41 is set to be larger, which helps to improve the fixing effect of the electrical connection line 3 on the first surface of the cell, strengthen the welding effect between the electrical connection line 3 and the first current collector electrode, and thus improve the module yield.

[0079] The encapsulating film layer covers the surface of the battery string, which can be understood as covering both the front and back of the battery string. Photovoltaic modules may also include a backsheet, located on the back of the battery string. The backsheet is bonded to the back of the battery string via the encapsulating film layer on the back, thus protecting the photovoltaic module.

[0080] It is understood that the materials used in the adhesive film layer may include at least one of ethylene-vinyl acetate copolymer (EVA), ethylene-propylene copolymer (POE), and vinyl acetate-olefin-vinyl acetate copolymer (EPE).

[0081] It is understood that the material used for the second adhesive part 5 can be the same as or different from the material used for the first adhesive part 4. The materials of the front adhesive layer and the back adhesive layer can be the same or different, and the adhesive layer material can also be selected based on the back plate material.

[0082] In some embodiments, the distance T1 between the two ends of the first contact area 41 in the second direction is greater than the distance T2 between the two ends of the second contact area 51 in the second direction. (See reference) Figure 3a and Figure 3b This configuration helps to create a gentler angle at both ends of the first contact area 41 in the second direction compared to the second contact area 51, further improving the light collection efficiency of the first surface side of the battery cell 1, reducing the reflection of incident light between different materials, and allowing more incident light to be converted into electrical energy. Additionally, it improves the bonding reliability between the first adhesive portion 4 and the battery cell 1, thereby enhancing the fixation effect of the electrical connection wire 3 on the first surface side.

[0083] In some embodiments, the distance M1 between the two ends of the first contact area 41 in the first direction is greater than the distance M2 between the two ends of the second contact area 51 in the first direction. (See reference) Figure 3a and Figure 3b This configuration helps to create a gentler angle at both ends of the first contact area 41 in the first direction compared to the second contact area 51, further improving the light collection efficiency of the first surface side of the battery cell 1, reducing the reflection of incident light between different materials, and allowing more incident light to be converted into electrical energy. Similarly, it improves the bonding reliability between the first adhesive portion 4 and the battery cell 1, and enhances the fixing effect of the electrical connection wire 3 on the first surface side.

[0084] In some embodiments, the area enclosed by the edge contour of the first contact area 41 is larger than the area enclosed by the edge contour of the second contact area 51. This arrangement helps to form a gentler angle in the first contact area 41 compared to the second contact area 51, further improving the light collection efficiency of the first surface side of the battery cell 1, reducing the reflection of incident light between different materials, and allowing more incident light to be converted into electrical energy. Similarly, this improves the bonding reliability between the first adhesive portion 4 and the battery cell 1, thereby improving the fixing effect of the electrical connection wire 3 on the first surface side.

[0085] It should be noted that this application does not require that T1 is greater than T2, M1 is greater than M2, and the area enclosed by the edge contour of the first contact area 41 is greater than the area enclosed by the edge contour of the second contact area 51 at the same time. For example, T1 can be greater than T2 and M1 can be less than or equal to M2; or T1 can be less than or equal to T2 and M1 can be greater than M2.

[0086] In some embodiments, the ratio of the distance T1 between the two ends of the first contact area 41 in the second direction to the distance T2 between the two ends of the second contact area 51 in the second direction is (0.9~1.2):1. This configuration can improve the collection efficiency of incident light on the first surface side while minimizing the shading of the first adhesive portion 4 on the light-facing surface, thereby improving light utilization; at the same time, it ensures the connection strength between the electrical connection line 3 on the first and second surfaces and the current collecting electrode 2, enabling the photovoltaic module to operate stably.

[0087] For example, the ratio between T1 and T2 can be 0.9:1, 1:1, 1.1:1 or 1.2:1, or a range consisting of any two of the above values.

[0088] In some embodiments, the distance T1 between the two ends of the first contact area 41 in the second direction is 1710~1950μm, and the distance T2 between the two ends of the second contact area 51 in the second direction is 1620~1840μm. This arrangement reduces light shading on both surfaces of the battery while ensuring the reliability of the connection between the electrical connection line 3 and the battery cell. It should be noted that the first adhesive portion 4 on the first surface of the battery cell 1 causes a certain degree of incident light loss, which has a negative effect. This application designs the first contact area 41 to be larger, reducing the tilt angle of the adhesive portion and minimizing the negative impact of shading, while ensuring that T1 is within the aforementioned range, thus balancing the stability of the electrical connection line 3 and the power generation of the module.

[0089] Optionally, T1 can be, for example, 1710μm, 1750μm, 1780μm, 1800μm, 1850μm, 1900μm or 1950μm, or a range consisting of any two of the above values.

[0090] Optionally, T2 can be, for example, 1620μm, 1650μm, 1700μm, 1750μm, 1800μm or 1840μm, or a range consisting of any two of the above values.

[0091] In some embodiments, the ratio of the distance M1 between the two ends of the first contact area 41 in the first direction to the distance M2 between the two ends of the second contact area 51 in the first direction is (1.1~3):1. This arrangement provides sufficient fixation for the electrical connection wires 3 while improving the collection efficiency of incident light on the first surface side. During use, the electrical connection wires 3 on the front side of the solar cell typically bear a greater tensile force than those on the back side. Designing M1 to be larger than M2 helps to improve the connection reliability of the electrical connection wires 3 on the front side and strengthens the fixation effect. For example, when the solar cell 1 is moved, it greatly reduces the possibility of the electrical connection wires 3 detaching from the solar cell 1.

[0092] For example, the ratio between M1 and M2 can be 1.1:1, 1.5:1, 2:1, 2.5:1 or 3:1, or a range consisting of any two of the above values.

[0093] In some embodiments, the distance M1 between the two ends of the first contact area 41 in the first direction is 1805~2685μm, and the distance M2 between the two ends of the second contact area 51 in the first direction is 895~1575μm. Similarly, this reduces light shading on both surfaces of the battery while ensuring the reliability of the connection between the electrical connection line 3 and the battery cell. It should be noted that the first adhesive portion 4 on the first surface of the battery cell 1 causes a certain degree of incident light loss, which has a negative effect. This application designs the first contact area 41 to be larger, reducing the tilt angle of the adhesive portion and minimizing the negative impact of shading. Similarly, this ensures that M1 is within the aforementioned range, balancing the stability of the electrical connection line 3 and the power generation of the module.

[0094] Optionally, M1 can be, for example, 1805μm, 1850μm, 1900μm, 2000μm, 2100μm, 2200μm, 2300μm, 2400μm, 2500μm, 2600μm or 2685μm, or a range consisting of any two of the above values.

[0095] Optionally, M2 can be, for example, 895μm, 1000μm, 1100μm, 1200μm, 1300μm, 1400μm, 1500μm or 1575μm, or a range consisting of any two of the above values.

[0096] In some embodiments, the ratio of the distance T1 between the two ends of the first contact area 41 in the second direction to the distance M1 between the two ends of the first contact area 41 in the first direction is (0.6~1):1. The first surface of the battery cell 1 is directly exposed to sunlight and is subject to significant temperature changes and impacts. A larger M1 provides a secure connection to the electrical connection wire 3, strengthening the welding strength between the electrical connection wire 3 and the current collector electrode. A relatively smaller T1 adjusts the area of ​​the first contact area 41 to a suitable range, providing sufficient fixation while reducing shading of the battery cell 1 and improving light utilization.

[0097] Optionally, the ratio between T1 and M1 can be 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1:1, or a range consisting of any two of the above values.

[0098] In some embodiments, the ratio of the distance T2 between the two ends of the second contact area 51 in the second direction to the distance M2 between the two ends of the second contact area 51 in the first direction is (1~2):1. This design ensures bonding effect while reducing the overall size, thereby reducing the obstruction of the second adhesive part 5 to incident light in the first direction, improving the utilization of back light incident light, and helping to improve the double-sided ratio.

[0099] Optionally, the ratio between T2 and M2 can be 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1, or a range consisting of any two of the above values.

[0100] In some embodiments, the ratio of the distance T1 between the two ends of the first contact area 41 in the second direction to the distance M1 between the two ends of the first area 41 in the first direction is less than the ratio of the distance T2 between the two ends of the second contact area 51 in the second direction to the distance M2 between the two ends of the second contact area 51 in the first direction. With this configuration, the first adhesive portion 4 has a gentler slope on its first surface compared to the second adhesive portion 5 on its second surface, further enhancing the light collection efficiency of the incident light on the first surface of the solar cell 1 and further improving the power generation of the module.

[0101] In some embodiments, the projection of the first adhesive portion 4 and / or the second adhesive portion 5 onto the surface of the battery cell 1 is any one of a rhombus or a rhombus-like shape, an ellipse or an ellipse-like shape; or the projection contour of the first adhesive portion 4 and / or the second adhesive portion 5 onto the surface of the battery cell 1 is any one of a parabola-like shape or a cosine curve on one side of the electrical connection line 3 along the second direction. Such shapes can better achieve sufficient fixation of the electrical connection line 3.

[0102] In some implementations... Figure 4 A cross-sectional schematic diagram of the first adhesive portion according to an embodiment of this application is shown. Please refer to... Figure 4 The distance A between one end of the first adhesive portion 4 along the second direction and the electrical connection line 3 at least partially covered by the first adhesive portion 4 is given by A. The ratio of A to the width X of the electrical connection line 3 along the second direction is A = aX, and 2 ≤ a ≤ 8. This helps to save on the cost of materials used in the first adhesive portion 4 and improves the bonding yield between the electrical connection line 3 and the battery cell 1.

[0103] Similar to the first adhesive portion 4, the distance between one end of the second adhesive portion 5 and the electrical connection line 3 at least partially covered by the second adhesive portion 5 can also be aX, where 2≤a≤8. For reasons similar to those described above, further details will not be provided here.

[0104] For example, 'a' can be 2, 3, 4, 5, 6, 7, or 8, or a range consisting of any two of the above values.

[0105] In some embodiments, the width X of the electrical connection wire 3 along the second direction is ≥0.1mm and ≤2mm. Within this width range, it is beneficial to achieve a better welding effect.

[0106] Optionally, the width X of the electrical connection line 3 along the second direction can be, for example, 0.1mm, 0.25mm, 0.5mm, 0.75mm, 1mm, 1.5mm or 2mm, or a range consisting of any two of the above values.

[0107] As mentioned above, the electrical connection wire 3 can have a cross-sectional area of ​​any shape. For example, taking a circular cross-sectional area as an example, 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. Even more preferably, the diameter of the electrical connection wire 3 is ≥0.14mm and ≤0.28mm. This configuration enhances the connection effect between the electrical connection wire 3 and the battery cell.

[0108] Taking the cross-sectional area of ​​the electrical connection wire 3 as square as an example, the width X of the square electrical connection wire along the second direction is ≥0.5mm and X≤2mm; preferably, the width of the square electrical connection wire along the second direction is ≥0.5mm and X≤1mm.

[0109] In some embodiments, the distance M1 between the two ends of the first contact area 41 in the first direction is 1, and the edge of the first contact area 41 has a contour line. The area enclosed by the contour line and the electrical connection line 3 along either side of the second direction is S1, where S1 satisfies: A is consistent with the previous description and will not be repeated here.

[0110] The area S1 can be understood as the area enclosed by the edge contour of the first adhesive part 4 on either side of the electrical connection line 3 along the second direction, on the surface of the solar cell 1, and the boundary of the electrical connection line 3 projected perpendicular to the direction of the solar cell 1. The edge contour can be obtained through image capture or other methods. Setting the area S1 within the aforementioned range ensures that the first adhesive part 4 provides sufficient fixation for the electrical connection line 3, improving the yield of the photovoltaic module; it also avoids waste of adhesive material. If the area S1 is too large, it will result in waste of adhesive material and may come into contact with adjacent current collector electrodes 2, adversely affecting conductivity; if the area S1 is too small, it will not provide adequate fixation, and the electrical connection line 3 may detach, reducing the reliability of the connection between the electrical connection line 3 and the solar cell 1.

[0111] Similar to the first contact area 41, the second contact area 51 is at a distance M2 between its two ends in the first direction, and the edge of the second contact area 51 has a contour line. The area enclosed by the contour line and the electrical connection line 3 along either side of the second direction is S2, where S2 satisfies: A is consistent with the previous description and will not be repeated here. Adjusting S2 within the above range has a similar effect to S1 and will not be repeated here.

[0112] In some embodiments, the distance M1 between the two ends of the first contact area 41 in the first direction is greater than the distance N1 between two adjacent first collector electrodes. Figure 5 A distribution diagram of the first adhesive portion and the first current collector electrode according to an embodiment of this application is shown. Figure 5 As shown, this arrangement helps to form a more secure fixation for the electrical connection wire 3, strengthens the connection strength between the electrical connection wire 3 and the battery cell 1, and between the electrical connection wire 3 and the first current collector electrode. When subjected to impact, the fixing effect of the first adhesive part 4 can prevent the welding position between the electrical connection wire 3 and the first current collector electrode from being directly subjected to force, thereby avoiding situations such as poor welding or broken welding, and strengthening the connection effect between the three.

[0113] It should be noted that the first adhesive part 4 can be as follows: Figure 5 The area shown covers the connection position between two adjacent first collector electrodes and electrical connection lines 3, which enhances the welding effect between the first collector electrodes and electrical connection lines 3 and avoids the possibility of broken welds or incomplete welds caused by direct force at the connection point; it can also cover the connection position between one first collector electrode and electrical connection line 3, and this application does not make any special limitation on this.

[0114] In some embodiments, the distance M2 between the two ends of the second contact area 51 in the first direction is greater than the distance between two adjacent second current collector electrodes. It can be understood that the second contact area 51 is arranged in a similar manner to the first contact area 41, and has a similar effect, which helps to strengthen the connection strength between the second current collector electrode, the electrical connection line 3 and the battery cell 1, which will not be elaborated further here.

[0115] In some embodiments, the ratio of the distance M1 between the two ends of the first contact area 41 in the first direction to the distance N1 between two adjacent first current collectors is (1.9~2.9):1. This arrangement allows the first adhesive portion 41 to contact the first current collector, increasing the adhesion of the first adhesive portion 41 and strengthening its fixing effect.

[0116] Optionally, the ratio of M1 to N1 can be, for example, 1.9:1, 2:1, 2.3:1, 2.5:1, 2.7:1 or 2.9:1, or a range consisting of any two of the above values.

[0117] In some embodiments, the ratio of the distance M2 between the two ends of the second contact area 51 in the first direction to the distance between two adjacent second current collectors is (1.1~2.3):1. This arrangement allows the second adhesive portion 51 to contact the second current collector, increasing the adhesion of the second adhesive portion 51 and strengthening its fixing effect.

[0118] Optionally, the ratio of the two can be, for example, 1.1:1, 1.5:1, 2:1, 2.1:1 or 2.3:1, or a range consisting of any two of the above values.

[0119] In some embodiments, along the first direction, the distance between the geometric center of the first adhesive portion 4 and / or the second adhesive portion 5 located on an electrical connection line 3 closest to the edge of the battery cell and the edge of the battery cell is s, where s ≥ 4 mm and ≤ 24 mm. Figure 6 A partial top view of a photovoltaic module near the edge of an embodiment of this application is shown. Figure 6 Taking the second surface of the solar cell 1 as an example, the positional relationship between the adhesive portion and the edge of the solar cell is schematically shown. This setting ensures the connection effect between the electrical connection wire 3 and the solar cell 1, avoiding bending or warping of the electrical connection wire 3 at the edge of the solar cell, thus improving the yield of the module. If s is too large, the electrical connection wire 3 may warp at the edge, leading to poor contact when the solar cells 1 are connected in series. If s is too small, there are more restrictions on the electrical connection wire 3, making it more rigid and difficult to form a certain degree of bending, which greatly restricts the position between the interconnected solar cells 1.

[0120] Optionally, s can be, for example, 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm or 24mm, or a range consisting of any two of the above values.

[0121] It should be noted that during the process of connecting multiple battery cells 1 in series to form a battery string, if the outermost first adhesive portion 4 and / or second adhesive portion 5 of adjacent battery cells 1 deviate from the welding requirements, the bonding effect between the electrical connection wire 3 and the battery cell 1 may be poor, which may lead to poor soldering or poor module reliability. Adjusting s within the aforementioned range can further improve the connection strength between the end of the electrical connection wire 3 and the battery cell 1, thereby improving the module reliability.

[0122] It is understandable that the distance between the first adhesive portion 4 of the battery cell 1 and the edge of the battery cell can differ from the distance between the corresponding second adhesive portion 5 and the edge of the battery cell in the thickness direction. This avoids applying adhesive at the same location and prevents the battery cell 1 from being raised at the same position, which could lead to possible issues such as cell cracking, microcracks, or bending.

[0123] In some embodiments, along the first direction, the distance between the geometric centers of adjacent first adhesive portions 4 or adjacent second adhesive portions 5 located on the same electrical connection line 3 is d, where d ≤ 16 mm. Continuing as... Figure 6 As shown, if d is greater than the aforementioned range, the fixing 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 collector electrode 2. It should be noted that a smaller d is not necessarily better. If d is smaller, it leads to a larger number of adhesive parts (first adhesive part 4 or second adhesive part 5), increasing the cost of adhesive materials and negatively impacting the photoelectric conversion efficiency of the component. For example, due to limitations in screen printing processes, d needs to be >0.1mm.

[0124] Optionally, d can be, for example, 0.5mm, 1mm, 3mm, 5mm, 7mm, 9mm, 11mm, 13mm, 15mm or 16mm, or a range consisting of any two of the above values.

[0125] In some embodiments, the difference between the number of first adhesive portions 4 bonded to any electrical connection line 3 connecting two adjacent battery cells 1 and the number of second adhesive portions 5 on the same electrical connection line 3 is 0 to 5. When both numbers are the same, the same template can be used for both the front and back of the battery cell, making the process simpler. Increasing the number of first adhesive portions 4 helps to strengthen the fixing effect of the front to the electrical connection line 3, improve the impact resistance of the front, and take into account the yield, stability and durability of the module. The second adhesive portions 5 on the back of the battery have better wrapping properties for the electrical connection line 3, and the back of the battery cell is usually less impacted, so the number of second adhesive portions 5 on the back can be reduced, thereby saving the amount of adhesive material used while enabling the battery cell 1 to have better bi-sided power generation.

[0126] Optionally, the difference in the number of the first adhesive portion 4 and the second adhesive portion 5 on the same electrical connection wire 3 can be, for example, 0, 1, 2, 3, 4 or 5, preferably >0.

[0127] In some embodiments, the number of first adhesive portions 4 on the first surface of any electrical connection line 3 connecting two adjacent battery cells 1 is 4 to 15, and the number of second adhesive portions 4 on the same electrical connection line 3 on the second surface is 4 to 15. This arrangement enhances the fixing effect on the electrical connection line 3 while reducing light loss caused by shading.

[0128] Optionally, on any electrical connection line 3, the number of first adhesive portions 4 located on the first surface can be 4, 5, 6, 8, 10, 12, 14, or 15, or a range consisting of any two of the aforementioned values. Similarly, on the same electrical connection line 3, the number of second adhesive portions 5 located on the second surface can be 4, 5, 6, 8, 10, 12, 14, or 15, or a range consisting of any two of the aforementioned values.

[0129] Understandably, among the multiple electrical connection lines 3 on the first surface, the number of first adhesive portions 4 on each electrical connection line 3 may be the same or different, and can be adjusted according to actual needs.

[0130] The first adhesive portions 4 on adjacent electrical connection lines 3 on the first surface can be staggered in the second direction. This arrangement helps to secure more adjacent first collector electrodes while fully securing the electrical connection lines 3, thereby improving the connection reliability between the electrical connection lines 3 and the first collector electrodes.

[0131] Understandably, among the multiple electrical connection lines 3 on the second surface, the number of second adhesive portions 5 on each electrical connection line 3 may be the same or different, and can be adjusted according to actual needs.

[0132] The second adhesive portions 5 on adjacent electrical connection lines 3 on the second surface can be staggered in the second direction. This arrangement helps to secure more adjacent second collector electrodes while fully securing the electrical connection lines 3, thereby improving the connection reliability between the electrical connection lines 3 and the second collector electrodes.

[0133] In some embodiments, the projections of the plurality of first adhesive portions 4 located on the first surface and the plurality of second adhesive portions 5 located on the second surface in the direction perpendicular to the surface of the solar cell are staggered. This arrangement avoids simultaneously raising the front and back sides of the solar cell 1 at the same location, which would cause stress concentration and potentially lead to microcracks or fragmentation during pressing. The staggered arrangement disperses stress, helping to maintain the integrity of the solar cell and improve the yield of the module.

[0134] In some embodiments, the battery string also includes: a plurality of end connection points 7 and at least two extension electrodes 8. Figure 7a A partial top view of the edge of a battery cell according to an embodiment of this application is shown; Figure 7b A partial top view of the edge of a battery cell according to another embodiment of this application is shown. Figures 7a-7b As shown, multiple end connection points 7 are located at both ends of the battery cell near the edge of the battery cell along the first direction.

[0135] In some embodiments, multiple end connection points 7 can be arranged parallel to each other along a first direction at the connection positions between the electrical connection line 3 and the collector electrode 2, reducing the possibility of the electrical connection line 3 becoming unsoldered or poorly soldered. In some embodiments, it can be as follows: Figure 7a As shown, in the first direction pointing towards the edge of the solar cell, the width of the multiple end connection points 7 can gradually increase along the second direction. This arrangement strengthens the connection strength of the electrical connection lines 3 near the edge of the solar cell, improving the yield of the module. In other embodiments, it can be as follows... Figure 7b As shown, in the first direction pointing towards the edge of the solar cell, the width of multiple end connection points 7 along the second direction can be the same; optionally, the multiple end connection points 7 can be spaced apart, which can be understood as the current collector 2 near the edge of the solar cell being positioned between two end connection points 7. This arrangement ensures good connection strength of the electrical connection lines 3 near the edge of the solar cell while reducing the waste of welding materials and saving costs.

[0136] At least two extended electrodes 8 are connected to the end connection point 7 closest to the edge of the solar cell and extend towards the edge of the solar cell, forming a harpoon structure with the extended electrodes 8 and the end connection point 7. The harpoon structure can be understood as... Figure 7a Right side or like Figure 7b The U-shaped structure on the left.

[0137] In some embodiments, the adhesive portion (first adhesive portion 4 or second adhesive portion 5) near the edge of the battery cell can be located within the harpoon structure. This arrangement provides a securing effect on the electrical connection wire 3 through the adhesive portion, reducing the pulling force on the end connection point 7 when the electrical connection wire 3 is bent or impacted at the edge, strengthening the electrical connection effect of the electrical connection wire 3, and improving the yield of the assembly. In other embodiments, the adhesive portion at the end can be located on the end connection point 7. This arrangement further strengthens the electrical connection effect of the electrical connection wire 3.

[0138] In some embodiments, the photovoltaic module further includes a bus electrode 6 extending along a first direction and electrically connected to at least a portion of the collector electrode 2, connecting two end connection points corresponding to each other along the first direction. For example... Figure 7a and Figure 7b As shown, to facilitate the distinction between the bus electrode 6 and the electrical connection line 3, in Figure 7a and Figure 7b Electrical connection line 3 is not marked, although Figure 7a and Figure 7b Electrical connection line 3 is not marked, but its location can be understood as being above the bus electrode 6. The presence of bus electrode 6 allows for fewer welding points, reducing the risk of battery warping and cracking due to thermal stress during the welding process.

[0139] In some embodiments, the number of electrical connection lines on the same surface of the battery cell is greater than or equal to the number of bus electrodes.

[0140] like Figure 7a , 7b The bus electrode 6 shown has a portion that extends into the harpoon structure, which enhances the safety redundancy of current collection and improves the yield of the component.

[0141] In some implementations, the spacing between adjacent solar cells along the first direction is -2 to 0 mm. This arrangement helps to increase the effective light-receiving area of ​​the module and improve the module's output power.

[0142] For example, the spacing between adjacent solar cells along the first direction can be -2mm, -1.5mm, -1mm, -0.5mm or 0mm, preferably -1 to 0mm.

[0143] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. 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, comprising a plurality of cell strings, each of the cell strings comprising: a plurality of cells, each of the cells having opposite first and second surfaces; a plurality of first current collecting electrodes on the first surface, extending along a second direction and arranged in parallel with a first direction interval; a plurality of second current collecting electrodes on the second surface, extending along the second direction and arranged in parallel with the first direction interval, the first direction intersecting the second direction; a plurality of electrical connecting lines extending along the first direction and connecting two adjacent cells; a plurality of first adhesive portions and a plurality of second adhesive portions, at least one of the first adhesive portions and at least one of the second adhesive portions adhering the electrical connecting lines and the cells; the first adhesive portions being on the first surface of the cells, the at least one of the first adhesive portions having a first contact area with the first surface of the cells; the second adhesive portions being on the second surface of the cells, the at least one of the second adhesive portions having a second contact area with the second surface of the cells; wherein the first contact area has a size different from that of the second contact area.

2. The photovoltaic module of claim 1, wherein, The photovoltaic module further comprises a layer of encapsulant covering the cell strings. wherein the first contact area has a size larger than that of the second contact area. 3.The photovoltaic module of claim 2, wherein: a distance between two ends of the first contact area in the second direction is greater than a distance between two ends of the second contact area in the second direction; and / or a distance between two ends of the first contact area in the first direction is greater than a distance between two ends of the second contact area in the first direction; and / or an area enclosed by an edge contour line of the first contact area is greater than an area enclosed by an edge contour line of the second contact area. 4.The photovoltaic module of claim 2, wherein: a ratio between the distance between the two ends of the first contact area in the second direction and the distance between the two ends of the second contact area in the second direction is (0.9-1.2) : 1; and / or the distance between the two ends of the first contact area in the second direction is 1710-1950 μm; and the distance between the two ends of the second contact area in the second direction is 1620-1840 μm. 5.The photovoltaic module of claim 2, wherein: a ratio between the distance between the two ends of the first contact area in the first direction and the distance between the two ends of the second contact area in the first direction is (1.1-3) : 1; and / or the distance between the two ends of the first contact area in the first direction is 1805-2685 μm; and the distance between the two ends of the second contact area in the first direction is 895-1575 μm. 6.The photovoltaic module of claim 2, wherein: a ratio between the distance between the two ends of the first contact area in the second direction and the distance between the two ends of the first contact area in the first direction is (0.6-1) : 1; and / or the distance between the two ends of the first contact area in the second direction is 1710-1950 μm; and the distance between the two ends of the first contact area in the first direction is 1805-2685 μm. The ratio of the distance between the two ends of the second contact region in the second direction to the distance between the two ends of the second contact region in the first direction is (1-2):

1.

7. The photovoltaic module of claim 6, wherein, The ratio of the distance between the two ends of the first contact region in the second direction to the distance between the two ends of the first contact region in the first direction is less than the ratio of the distance between the two ends of the second contact region in the second direction to the distance between the two ends of the second contact region in the first direction.

8. The photovoltaic module according to any one of claims 1-7, wherein, The distance between the two ends of the first contact region in the first direction is greater than the distance between two adjacent first current collecting electrodes; and / or, The distance between the two ends of the second contact region in the first direction is greater than the distance between two adjacent second current collecting electrodes.

9. The photovoltaic module according to claim 8, wherein, The ratio of the distance between the two ends of the first contact region in the first direction to the distance between two adjacent first current collecting electrodes is (1.9-2.9): 1; and / or, The ratio of the distance between the two ends of the second contact region in the first direction to the distance between two adjacent second current collecting electrodes is (1.1-2.3):

1.

10. The photovoltaic module of any of claims 1-9, wherein, The projection of the first bonding part and / or the second bonding part on the surface of the cell sheet is any one of a rhombus or a rhombus-like shape, an ellipse or an ellipse-like shape; Or the projection profile of the first bonding part and / or the second bonding part on the surface of the cell sheet is any one of a parabolic-like shape, a cosine curve-like shape on the side of the electrical connection wire along the second direction.

11. The photovoltaic module of any of claims 1-10, wherein, Along the first direction, the distance between the geometric center of the first bonding part and / or the second bonding part closest to the edge of the cell sheet on the electrical connection wire and the edge of the cell sheet is s, s≥4mm, and ≤24mm.

12. The photovoltaic module of any of claims 1-11, wherein, Along the first direction, the distance between the geometric centers of adjacent first bonding parts or adjacent second bonding parts on the same electrical connection wire is d, d≤16mm.

13. The photovoltaic module of claims 1-12, wherein, The difference between the number of first bonding parts and the number of second bonding parts bonded on the electrical connection wire connecting two adjacent cell sheets is 0-5; and / or; The number of first bonding parts on the electrical connection wire located on the first surface is 4-15, and the number of second bonding parts on the same electrical connection wire located on the second surface is 4-15.

14. The photovoltaic module of any of claims 1-13, wherein, Further comprising: A plurality of end connection points located in the two end regions of the cell sheet along the first direction; At least two extension electrodes connected to the end connection points closest to the edge of the cell sheet and extending toward the edge of the cell sheet, the extension electrodes and the end connection points forming a fishing-tackle structure; Wherein, the first bonding part or the second bonding part closest to the edge of the cell sheet is located in the fishing-tackle structure or on the end connection point.

15. The photovoltaic module of claim 14, wherein, Further comprising: A bus electrode extending in the first direction, the bus electrode being electrically connected to at least part of the current collecting electrodes, and connecting two of the end connecting points corresponding in the first direction; wherein the number of the electric connecting lines on the same surface of the battery piece is greater than or equal to the number of the bus electrodes; or The bus electrode located at the edge of the battery piece has a portion extending into the fish-tail structure.

Images