Photovoltaic module and photovoltaic system

Abstract

A photovoltaic module and a photovoltaic system. The photovoltaic module comprises: cells, the cells each having a first surface and a second surface opposite to each other; a plurality of interconnection members, a plurality of cells being connected in series by means of the interconnection members, a plurality of interconnection members being spaced apart from each other on the first surfaces of the cells, and a plurality of interconnection members being spaced apart from each other on the second surfaces of the cells; first adhesive layers, the first adhesive layers being laid on the first surfaces of the cells, and the first adhesive layers being located on the side of the interconnection members, which are arranged on the first surfaces, facing away from the cells; and second adhesive layers, the second adhesive layers being laid on the second surfaces of the cells, the second adhesive layers being located on the side of the interconnection members, which are arranged on the second surfaces, facing away from the cells, and the peeling force between the second adhesive layers and the cells being greater than the peeling force between the first adhesive layers and the cells. In this way, the bonding force between the second adhesive layers and the cells is greater, and thus the second adhesive layers are more firmly bonded, even after long-term use under the action of gravity, delamination of the second adhesive layers is less likely to occur, thus reducing the risk of delamination, and prolonging the service life of photovoltaic modules.

Description

Photovoltaic modules and photovoltaic systems Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic module and a photovoltaic system. Background Technology

[0002] Photovoltaic modules contain strings of cells, which are the core component of the module and convert solar energy into electrical energy. A cell string typically consists of multiple cells spaced apart, connected in series with adjacent cells via solder strips to collect the current generated by the multiple cells.

[0003] Photovoltaic modules are typically laid at an angle during use. After prolonged use, delamination often occurs on the back of the photovoltaic modules, affecting their lifespan. Summary of the Invention

[0004] The purpose of this application is to provide a photovoltaic module and a photovoltaic system to reduce the phenomenon of back delamination of photovoltaic modules and extend the service life of photovoltaic modules.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A photovoltaic module, comprising:

[0007] The solar cell has a first surface and a second surface that are opposite each other.

[0008] Multiple interconnecting elements are used to connect multiple solar cells in series; multiple interconnecting elements are arranged at intervals on the first surface of the solar cell and multiple interconnecting elements are arranged at intervals on the second surface of the solar cell.

[0009] The first adhesive layer is laid on the first surface of the battery cell, and the first adhesive layer is located on the side of the interconnect on the first surface away from the battery cell.

[0010] The second adhesive layer is laid on the second surface of the battery cell, and the second adhesive layer is located on the side of the interconnect on the second surface away from the battery cell.

[0011] The peel force between the second adhesive layer and the second surface is greater than the peel force between the first adhesive layer and the first surface.

[0012] By adopting the above technical solution, in the practical application of photovoltaic modules, the second surface can be the backlight surface, and the first surface the light-facing surface. After the photovoltaic modules are installed, the second surface is horizontal or tilted downwards. Because the peel force between the second adhesive layer and the second surface of the solar cell is greater than the peel force between the first adhesive layer and the first surface of the solar cell, the adhesion of the second adhesive layer is greater and the adhesion is stronger. Even under the action of gravity for a long time, or when encountering vibration or shaking, the second adhesive layer is less likely to delaminate, reducing the risk of delamination and thus extending the service life of the photovoltaic modules.

[0013] In one implementation, the difference between the peel force between the second adhesive layer and the second surface and the peel force between the first adhesive layer and the first surface is 0.2N-1.9N. This technical solution ensures a stronger bond to the second adhesive layer, reducing the risk of delamination; moreover, it prevents the difference between the peel force between the second adhesive layer and the second surface and the peel force between the first adhesive layer and the first surface from becoming too large, thus reducing processing difficulty.

[0014] In one implementation, the first adhesive layer has multiple pressing points, and the second adhesive layer has multiple pressing points; with this configuration, during the formation of the first adhesive layer, multiple pressing points can be formed using a pressing component, and the first adhesive layer can be bonded more firmly to the battery cell through the multiple pressing points.

[0015] Additionally or alternatively, the projections of the bonding points on the first adhesive layer and the bonding points on the second adhesive layer onto the solar cell do not overlap at least partially; thus, the problems of increased warping and increased bubbling caused by the overlap of bonding points on the first and second adhesive layers can be avoided.

[0016] Additionally or alternatively, the peel force between the second adhesive layer and the interconnect located on the second surface is greater than the peel force between the first adhesive layer and the interconnect located on the first surface. This can further increase the bonding reliability of the second adhesive layer, and also increase the bonding reliability between the second surface and the interconnect.

[0017] In one implementation, the length of the first adhesive layer is greater than the length of the second adhesive layer along the extension direction of the interconnect. This configuration, where the first adhesive layer is longer than the second, allows the edge of the first adhesive layer to be closer to the edge of the solar cell than the edge of the second adhesive layer. Consequently, the first adhesive layer has a longer layup length along the extension direction of the interconnect, making it less prone to lifting. It also reduces the height difference between the edge of the solar cell and the encapsulating film, decreasing the formation of air bubbles and improving product yield.

[0018] In one implementation, the length of the first adhesive layer is greater than or equal to 0.9 in the extension direction of the interconnect. This technical solution makes the edge of the first adhesive layer closer to the edge of the battery cell, and the laying length of the first adhesive layer is longer in the extension direction of the interconnect, making it less prone to lifting. It also reduces the height difference or step between the edge of the battery cell and the encapsulation film, reduces the generation of bubbles, and improves the product yield.

[0019] Alternatively, along the extension direction of the interconnect, the ratio of the length of the second adhesive layer to the length of the solar cell is greater than or equal to 0.82. This configuration allows for a reduction in the length of the second adhesive layer compared to the first, thereby saving raw materials and reducing manufacturing costs.

[0020] In one implementation, the photovoltaic module includes multiple solar cells, including a first solar cell and a second solar cell. An interconnect connects the front electrode of the first surface of the first solar cell and the back electrode of the second surface of the second solar cell. The first solar cell and the second solar cell overlap to form an overlapping region. Along the extension direction of the interconnect, a first adhesive layer located on the first surface of the first solar cell extends to the overlapping region.

[0021] In one implementation, along the extension direction of the interconnect, the first adhesive layer located on the first surface of the first cell extends at least to half the width of the overlapping region, the width direction of the overlapping region being consistent with the extension direction of the interconnect.

[0022] In one implementation, along the extension direction of the interconnect, a first adhesive layer located on the first surface of the first battery cell covers the edge of the first battery cell.

[0023] In one implementation, the first encapsulating film located on the first and second surfaces of the first solar cell does not overlap with the second encapsulating film located on the first and second surfaces of the second solar cell in the thickness direction. This technical solution avoids excessive overlap that could lead to microcracks in the solar cell.

[0024] In one implementation, along the extension direction of the interconnect, the distance between the first adhesive layer on the first surface of the first battery cell and the pad on the second surface of the second battery cell adjacent to the first battery cell is D, where D ≥ 3 mm.

[0025] In one implementation, a portion of the first adhesive layer located on the first surface of the first cell, in the overlapping region, penetrates between the first cell and the interconnect.

[0026] In one implementation, the projected area of ​​the first adhesive layer on the solar cell is larger than that of the second adhesive layer. This design allows for a larger coverage area of ​​the first adhesive layer, resulting in greater coverage of the interconnects on the solar cell. This reduces the risk of edge lifting of the first adhesive layer, decreases bubble formation, and improves product yield.

[0027] In one implementation, the distance between the edge of the first adhesive layer and the edge of the battery cell along the extension direction of the interconnect is d1, where 0mm≤d1≤1mm. Thus, the coverage length of the first adhesive layer along the extension direction of the interconnect is relatively long, which can reduce the displacement and shaking of the interconnect and improve the welding reliability of the interconnect.

[0028] Alternatively, along the extension direction of the interconnect, the distance between the edge of the second adhesive layer and the edge of the solar cell is d2, where 0mm ≤ d2 ≤ 5mm. With this configuration, the gap between the edge of the second adhesive layer and the edge of the solar cell can be appropriately increased, and the length of the second adhesive layer can be appropriately reduced, thereby lowering the accuracy requirements for its installation and increasing the installation rate.

[0029] In one implementation, on the first and second surfaces of the battery cell, along a direction perpendicular to the length of the interconnect, the edge of the first adhesive layer and / or the second adhesive layer extends beyond the outermost interconnect by a distance d3, where d3 ≥ 3 mm. This technical solution ensures that the outermost interconnect has a sufficiently wide first or second adhesive layer to bond with the battery cell, and also ensures that all interconnects on the battery cell surface are covered by the first or second adhesive layer, thereby reducing the problem of the first and second adhesive layers lifting in this direction. Along a direction perpendicular to the length of the interconnect, the distance between the edge of the first and / or second adhesive layer and the edge of the battery cell is d4, where d4 ≥ 1 mm. This technical solution provides a suitable gap between the first or second adhesive layer and the edge of the battery cell, allowing for continuous identification of the relative position between the battery cell and the first or second adhesive layer during interconnect welding, preventing positional deviations and improving product yield.

[0030] In one implementation, along a direction perpendicular to the length of the interconnect, the first surface includes an adjacent first region and a second region. Compared to the second region, the first region is located closer to the edge of the first surface. A first adhesive layer covers the second region but does not cover the first region, and an encapsulating film is applied to the first region. With this technical solution, during the encapsulation process, the encapsulating film is partially bonded to the first adhesive layer and partially bonded to the first region on the battery cell, which can improve the fixation reliability between the encapsulating film and the battery cell.

[0031] Alternatively or additionally, the second surface includes a third region and a fourth region surrounding the third region, the second adhesive layer covers the third region but not the fourth region, and an encapsulating film is applied to the fourth region. Using this technical solution, for the solar cell, the encapsulating film is fixedly bonded to the perimeter of the solar cell and to the second adhesive layer in the center, which can improve the fixation reliability between the solar cell, the encapsulating film, and the second adhesive layer.

[0032] In one implementation, the first and second adhesive layers are made of different materials. Depending on the specific application, either the first or second adhesive layer can be made of a lower-cost material, thereby reducing the manufacturing cost of the photovoltaic module.

[0033] In one implementation, the first surface is the front side of the solar cell; the photovoltaic module also includes an encapsulating film located on the side of the first adhesive layer opposite to the solar cell; the encapsulating film can protect the solar cell from external water, oxygen, etc.

[0034] The first adhesive layer and / or encapsulating film include an anti-PID material, which has non-polar molecules with saturated bonds, effectively preventing PID phenomena; and / or, the first adhesive layer and / or encapsulating film contain a non-polar material. This allows the first surface of the solar cell, i.e., the light-facing side, to have better anti-PID, heat aging resistance, and UV resistance properties.

[0035] In one implementation, the first adhesive layer and / or the encapsulating film comprises a polyolefin elastomer (POE). POE has nonpolar molecules with saturated bonds, so using POE to make the first adhesive layer and / or the encapsulating film on the side of the first adhesive layer away from the battery cell can effectively prevent PID (Polydioxanone) phenomenon.

[0036] Alternatively, the first adhesive layer comprises multiple stacked sub-adhesive layers, at least one of which is a POE layer; or, the encapsulating film comprises multiple stacked sub-adhesive layers, at least one of which is a POE layer. In this case, a single POE layer covering the entire surface of the solar cell provides comprehensive anti-PID protection, and since no POE material is used in the module for areas such as cell gaps, string gaps, and module edge gaps, cost can be reduced while still providing anti-PID protection.

[0037] In one implementation, the degree of crosslinking of the first adhesive layer is different from that of the second adhesive layer; and / or, the degree of crosslinking of both the first and second adhesive layers is greater than or equal to 60% and less than or equal to 96%, in order to improve the fixation reliability of the first and second adhesive layers and the battery cell.

[0038] In one implementation, the first surface is the front side of the solar cell; the crosslinking degree of the first adhesive layer is less than that of the second adhesive layer; and / or, the difference between the crosslinking degree of the first adhesive layer and the crosslinking degree of the second adhesive layer is 2%-25%; at this time, the difference in crosslinking degree between the first adhesive layer and the second adhesive layer is appropriate, and the requirements for lamination temperature are relatively consistent, which can simplify the process difficulty and improve the efficiency and yield of photovoltaic module manufacturing.

[0039] Alternatively or additionally, the water vapor transmission rate of the first adhesive layer is lower than that of the second adhesive layer. When the water vapor transmission rate of the first adhesive layer is lower, it provides a better water vapor barrier effect for the photovoltaic module compared to the second adhesive layer, thus providing a better water vapor barrier effect at a lower cost.

[0040] In one implementation, the height of the interconnect is X along the thickness direction of the solar cell, and the thickness of the first adhesive layer and / or the second adhesive layer not covering the interconnect is h, where h = m1 * X, and 0.42 ≤ m1 ≤ 0.65. This setting keeps the thickness of the first adhesive layer and / or the second adhesive layer within a reasonable range, which can reduce air bubbles in the first and second adhesive layers and also prevent the first adhesive layer and / or the second adhesive layer from being too thick and affecting the light absorption efficiency of the solar cell.

[0041] Additionally or alternatively, the thickness of the first adhesive layer and / or the second adhesive layer is h, 80μm≤h≤120μm; this thickness of the first and second adhesive layers can reduce the risk of adhesive layer bubbles and warping while also taking cost into consideration.

[0042] Additionally or alternatively, the basis weight of the first adhesive layer and / or the second adhesive layer is y1, where y1 = ρ1 * m1 * X, ρ1 is the density of the first or second adhesive layer, and the unit of ρ1 is g / m³. 3 The unit of X is m, and the unit of y1 is g / m. 2 This ensures the weight of the first and / or second adhesive layers, thereby guaranteeing a good encapsulation effect.

[0043] In one implementation, the photovoltaic module further includes an encapsulating film disposed on the side of the first adhesive layer facing away from the solar cell and on the side of the second adhesive layer facing away from the solar cell; the thickness of the encapsulating film is greater than or equal to 240 μm to ensure the encapsulation effect; and / or, the weight of the encapsulating film is y2, y2=[(1-m2)*X+d]*ρ2, where d represents the minimum distance from the interconnect to the inner side of the cover plate of the photovoltaic module, X is the height of the interconnect, and ρ2 is the density of the encapsulating film, 0.4≤m2≤0.6, where the unit of ρ2 is g / m³. 3 The unit of X is m, and the unit of y2 is g / m. 2 With this configuration, for interconnect components of a certain height, the basis weight of the encapsulating film of the photovoltaic module satisfies the above formula, thus providing sufficient moisture barrier effect and support function.

[0044] In one implementation, the photovoltaic module further includes an encapsulating film disposed on the side of the first adhesive layer facing away from the solar cell and on the side of the second adhesive layer facing away from the solar cell; the total thickness of the first adhesive layer and the encapsulating film at position A is less than the total thickness at position B; and / or, the total thickness of the second adhesive layer and the encapsulating film at position A is less than the total thickness at position B; position A is the position corresponding to the interconnect, i.e., the position covering the interconnect, and position B is the position not covering the interconnect. With this configuration, positions B of the first and second adhesive layers, as well as a portion of the encapsulating film at position B, are all located on the side of the interconnect; the side of the interconnect has the first or second adhesive layer at the bottom and the encapsulating film at the top; at this time, the entire side of the interconnect is bonded, fixed, and limited, thereby improving the fixing effect of the interconnect and reducing the risk of interconnect displacement.

[0045] In one implementation, the first adhesive layer and / or the second adhesive layer are bonded to the side and top surfaces of the interconnect; and / or, the thickness of the first adhesive layer at position A is less than the thickness at position B; and / or, the thickness of the second adhesive layer at position A is less than the thickness at position B; position A is the position corresponding to the interconnect, i.e., the position covering the interconnect, and position B is the position not covering the interconnect. With this configuration, the larger amount of adhesive material at position B can fix and position the side of the interconnect, thus confining the interconnect within the strip area defined by the adhesive layer at position B, reducing the distortion of the interconnect; moreover, the bonding of the first and second adhesive layers to the side and top surfaces of the interconnect enhances the reliability of the interconnect fixation. Even if the bottom portion of the interconnect is not fixedly connected to the battery cell, the bonding of the top and side surfaces and the limiting effect of the adhesive layer at position B can greatly improve the alignment accuracy of the interconnect and reduce positional offset.

[0046] In one implementation, the thickness difference between positions A and B of the first adhesive layer is 0.03mm-0.05mm, and / or the thickness difference between positions A and B of the second adhesive layer is 0.03mm-0.05mm. When the thickness difference is within the above range, the thickness of the adhesive layer at the top of the interconnect is relatively moderate, which can improve the buffering and fixing effect.

[0047] According to another aspect of this application, a photovoltaic system is provided, comprising a photovoltaic module as described in any of the above.

[0048] Compared with the prior art, the beneficial effects of the photovoltaic system provided in this application are the same as those of the photovoltaic modules mentioned above, and will not be repeated here. Attached Figure Description

[0049] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0050] Figure 1 is a schematic diagram of a photovoltaic module provided in an embodiment of this application;

[0051] Figure 2 is a cross-sectional view of the photovoltaic module provided in this application, obtained by cutting the cell along a plane parallel to the length direction of the interconnect.

[0052] Figure 3 is a schematic diagram of the first surface of the solar cell of the photovoltaic module provided in the embodiment of this application;

[0053] Figure 4 is a schematic diagram of the first surface of a solar cell of a photovoltaic module provided in another embodiment of this application;

[0054] Figure 5 is a schematic diagram of the second surface of the solar cell of the photovoltaic module provided in the embodiment of this application;

[0055] Figure 6 is a cross-sectional view of the photovoltaic module provided in this application, obtained by cutting the cell along a plane perpendicular to the length direction of the interconnect.

[0056] Figure 7 is a schematic diagram obtained by cutting the solar cell of the photovoltaic module provided in the embodiment of this application along a plane parallel to the length direction of the interconnect.

[0057] Reference numerals: 1-Battery cell, 1a-First battery cell, 1b-Second battery cell, 2-Interconnector, 3-First adhesive layer, 3a-First adhesive layer of the first battery cell, 4-Encapsulation film, 5-Second adhesive layer, 5a-Second adhesive layer of the first battery cell, 5b-Second adhesive layer of the second battery cell, 6a-First solder pad, 6b-Second solder pad. Detailed Implementation

[0058] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0059] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified.

[0061] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0062] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0063] This application provides a photovoltaic module, which includes solar cells 1, interconnects 2, a first adhesive layer 3, and a second adhesive layer 5. Multiple solar cells 1 are connected in series via the interconnects 2. For example, Figure 1 provides a schematic diagram of multiple solar cells 1 electrically connected together. As shown in Figure 1, multiple solar cells 1 are arranged sequentially along a first direction to form a solar cell string, and the multiple solar cells 1 in the solar cell string are connected in series. Two or more solar cell strings are arranged sequentially along the first direction to form a group of solar cell strings, and multiple groups of solar cell strings are arranged sequentially along a second direction.

[0064] The solar cell 1 has a first surface and a second surface, that is, two surfaces opposite each other along the thickness direction of the solar cell 1 are the first surface and the second surface, respectively. In actual use, the first surface can correspond to the light-facing side of the solar cell 1, and the second surface can correspond to the back-facing side of the solar cell 1. Multiple interconnects 2 are used to electrically connect adjacent solar cells 1. Specifically, the solar cell 1 is a bifacial cell, with multiple interconnects 2 spaced apart on the first surface and multiple interconnects 2 spaced apart on the second surface of the solar cell 1. The charge carriers derived from the multiple interconnects 2 on the first surface and the multiple interconnects 2 on the second surface have opposite polarities.

[0065] As shown in Figure 2, a first adhesive layer 3 is laid on the first surface of the battery cell 1, and the first adhesive layer 3 is located on the side of the interconnect 2 facing away from the battery cell 1. That is, multiple interconnects 2 on the first surface are located between the battery cell 1 and the first adhesive layer 3, so as to fix multiple interconnects 2 on the first surface using the first adhesive layer 3. A second adhesive layer 5 is laid on the second surface of the battery cell 1, and the second adhesive layer 5 is located on the side of the interconnect 2 facing away from the battery cell 1. That is, multiple interconnects 2 on the second surface are located between the battery cell 1 and the second adhesive layer 5, so as to fix multiple interconnects 2 on the second surface using the second adhesive layer 5. In the gap between adjacent interconnects 2 on the first surface, the first adhesive layer 3 directly contacts and bonds to the area of ​​the battery cell 1 that is not covered by interconnects, and the first adhesive layer is bonded to the interconnects 2 on the first surface. In the gap between adjacent interconnects 2 on the second surface, the second adhesive layer 5 directly contacts and bonds to the area of ​​the battery cell 1 that is not covered by interconnects 2, and the second adhesive layer is bonded to the interconnects 2 on the second surface.

[0066] The peel force between the second adhesive layer 5 and the second surface is greater than the peel force between the first adhesive layer 3 and the first surface. In other words, the force required to peel the second adhesive layer 5 from the second surface is greater than the force required to peel the first adhesive layer 3 from the first surface. During the testing process, the first adhesive layer can be peeled off the battery cell, and its peel force can be measured. The second adhesive layer can also be peeled off the battery cell, and its peel force can be measured.

[0067] By adopting the above technical solution, in the actual application of photovoltaic modules, the second surface can be the backlight surface, and the first surface can be the light-facing surface. After the photovoltaic modules are installed, the second surface can be horizontal or tilted downwards. Because the peel force between the second adhesive layer 5 and the second surface of the cell 1 is greater than the peel force between the first adhesive layer 3 and the first surface of the cell 1, the adhesion of the second adhesive layer 5 is greater, and the second adhesive layer 5 is more firmly bonded. Even under the action of gravity for a long time, or when encountering vibration or shaking, the second adhesive layer 5 is less likely to delaminate, reducing the risk of delamination and thus extending the service life of the photovoltaic modules.

[0068] In some embodiments, the difference between the peel force between the second adhesive layer 5 and the second surface and the peel force between the first adhesive layer 3 and the first surface is 0.2N-1.9N, that is, the peel force between the second adhesive layer 5 and the second surface is 0.2N-1.9N greater than the peel force between the first adhesive layer 3 and the first surface. This technical solution ensures a stronger bond to the second adhesive layer 5, reducing the risk of delamination; moreover, it prevents the difference between the peel force between the second adhesive layer 5 and the second surface and the peel force between the first adhesive layer 3 and the first surface from being too large, thus reducing processing difficulty. Optionally, the peel force between the second adhesive layer 5 and the battery cell 1 is 0.5N-1.5N greater than the peel force between the first adhesive layer 3 and the battery cell 1.

[0069] In some embodiments, the difference between the peel force between the second adhesive layer 5 and the battery cell 1 and the peel force between the first adhesive layer 3 and the battery cell 1 is 0.2N, 0.3N, 0.4N, 0.5N, 0.6N, 0.7N, 0.8N, 0.9N, 1.0N, 1.1N, 1.2N, 1.3N, 1.4N, 1.5N, 1.6N, 1.7N, 1.8N, or 1.9N or other suitable values.

[0070] The interconnecting component 2 can be a solder strip, and the cross-section of the solder strip can be circular, rectangular, triangular, etc.

[0071] In the actual processing of this photovoltaic module, the first surface of the solar cell 1 can face upwards. During the laying of the first adhesive layer 3, the gravity of the first adhesive layer 3 alone is insufficient to firmly bond it to the solar cell 1. Therefore, in some embodiments, the first adhesive layer 3 has multiple pressing points. With this configuration, multiple pressing points can be formed using a pressing component during the formation of the first adhesive layer 3, and these multiple pressing points can further strengthen the bond between the first adhesive layer 3 and the solar cell 1. It can be understood that the multiple pressing points can be multiple recessed points or areas on the first adhesive layer 3. These pressing points can be distributed in multiple rows and columns on the first adhesive layer 3, or they can be distributed in multiple concentric rings, or they can be distributed irregularly, etc.

[0072] In some embodiments, the peel force between the second adhesive layer 5 and the interconnect 2 located on the second surface is greater than the peel force between the first adhesive layer 3 and the interconnect 2 located on the first surface. That is, the force required to peel the second adhesive layer 5 from the interconnect 2 on the second surface is greater than the force required to peel the first adhesive layer 3 from the interconnect 2 on the first surface. This further increases the bonding reliability of the second adhesive layer 5, and also increases the bonding reliability between the second surface and the interconnect 2.

[0073] In some embodiments, the first adhesive layer 5 has multiple bonding points. In some embodiments, the projections of the bonding points on the first adhesive layer 3 and the bonding points on the second adhesive layer 5 onto the solar cell do not overlap at least partially. For example, in some embodiments, the projections of the bonding points of the second adhesive layer 5 onto the solar cell include point m, where m is an integer greater than or equal to 1, while the projections of the bonding points of the first adhesive layer onto the solar cell do not coincide with point m, or do not completely coincide with it. This avoids the problems of increased warping and bubbling caused by the overlap of bonding points on the first adhesive layer 3 and the second adhesive layer 5.

[0074] During the welding of interconnect 2, the first surface of the battery cell 1 faces upward and the second surface faces downward. Therefore, the edge of the first adhesive layer 3 on the first surface is prone to lifting, especially under possible shaking or displacement of the interconnect 2. The second adhesive layer 5 on the second surface, however, is less prone to lifting due to the gravity of the battery cell 1 and the adsorption effect of the welding platform. When the edge of the first adhesive layer 3 lifts, a height difference exists between the encapsulation film 4 and the battery cell 1 during lamination, causing air bubbles to easily form near the edge of the battery cell 1, reducing yield. In view of the above, in some embodiments, the length of the first adhesive layer 3 is greater than the length of the second adhesive layer 5 along the extension direction of the interconnect 2. With this configuration, when the length of the first adhesive layer 3 is greater than the length of the second adhesive layer 5, the edge of the first adhesive layer 3 is closer to the edge of the battery cell 1 than the edge of the second adhesive layer 5. This results in a longer layup length of the first adhesive layer 3 along the extension direction of the interconnect 2, making it less prone to lifting, and also reduces the height difference between the edge of the battery cell 1 and the encapsulation film 4, reducing air bubble formation and improving product yield. Furthermore, since the risk of the second adhesive layer 5 warping is relatively small, its length can be appropriately reduced along the extension direction of the interconnect 2, thereby saving raw materials and reducing manufacturing costs. When the length of the first adhesive layer 3 is equal to the length of the second adhesive layer 5, the complexity of the processing technology can be reduced.

[0075] In some embodiments, the ratio of the length of the first adhesive layer 3 to the length of the battery cell 1 along the extension direction of the interconnect 2 is greater than or equal to 0.9. As shown in FIG. 3, along the extension direction of the interconnect 2, there may be a small gap between the edge of the first adhesive layer 3 and the edge of the battery cell 1; or, as shown in FIG. 4, along the extension direction of the interconnect 2, the edge of the first adhesive layer 3 coincides with the edge of the battery cell 1, in which case the length of the first adhesive layer 3 is equal to the length of the battery cell 1. This technical solution allows the edge of the first adhesive layer 3 to be closer to the edge of the battery cell 1, and along the extension direction of the interconnect 2, the laying length of the first adhesive layer 3 is longer, making it less prone to warping. It also reduces the height difference or step between the edge of the battery cell 1 and the encapsulating film 4, reducing the generation of bubbles and improving product yield. For example, in some embodiments, the ratio of the length of the first adhesive layer 3 to the length of the battery cell 1 along the extension direction of the interconnect 2 is 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1 or other suitable values.

[0076] In other embodiments, the length ratio of the second adhesive layer 5 to the length of the battery cell 1 along the extension direction of the interconnect 2 is greater than or equal to 0.82. As shown in FIG. 5, a large gap may be present between the edge of the first adhesive layer 3 and the edge of the battery cell 1 along the extension direction of the interconnect 2. With this configuration, the length of the second adhesive layer 5 can be appropriately reduced compared to the first adhesive layer 3, thereby saving raw materials for the second adhesive layer 5 and reducing manufacturing costs. For example, in some embodiments, the length ratio of the second adhesive layer 5 to the length of the battery cell 1 along the extension direction of the interconnect 2 is 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, or other suitable values.

[0077] From the perspective of coverage area, the projected area of ​​the first adhesive layer 3 on the solar cell 1 is larger than that of the second adhesive layer 5. This can be achieved by the first adhesive layer 3 having a longer length in the direction of the interconnect 2 than the second adhesive layer 5, or by the first adhesive layer 3 having both a longer length and a wider width than the second adhesive layer 5. Using this technical solution, the first adhesive layer 3 has a larger coverage area, providing greater coverage of the interconnect 2 on the solar cell 1. This reduces the risk of edge lifting of the first adhesive layer 3, decreases the generation of bubbles, and improves product yield. Furthermore, since the second adhesive layer 5 has a lower risk of lifting, its coverage area can be appropriately reduced, thereby saving raw materials for the second adhesive layer 5 and lowering manufacturing costs.

[0078] In some embodiments, the photovoltaic module includes multiple solar cells, including a first solar cell and a second solar cell. An interconnect connects the front electrode of a first surface of the first solar cell and the back electrode of a second surface of the second solar cell. The first and second solar cells overlap to form an overlapping region. Along the extension direction of the interconnect, a first adhesive layer located on the first surface of the first solar cell extends to the overlapping region. This design avoids hard contact between the overlapping region, the first and second solar cells, and the interconnect between them, reducing the probability of cell cracking. As shown in Figure 7, a plurality of battery cells include a first battery cell 1a and a second battery cell 1b. A first adhesive layer 3a is deposited on the first surface (e.g., the front side) of the first battery cell 1a, and a second adhesive layer 5a is deposited on the second surface (e.g., the back side) of the first battery cell 1a. A second adhesive layer 5b is deposited on the second surface (e.g., the back side) of the second battery cell 1b. An interconnect 2 (e.g., a solder ribbon) connects the front electrode of the first surface of the first battery cell 1a and the back electrode of the second surface of the second battery cell 1b. The first battery cell 1a and the second battery cell 1b overlap to form an overlapping region. Along the extension direction of the interconnect, the first adhesive layer on the first surface of the first battery cell 1a extends to the overlapping region. Figure 7 also schematically shows the first pad 6a of the first battery cell 1a and the second pad 6b of the second battery cell 1b.

[0079] In some embodiments, as shown in FIG7, along the extending direction of the interconnect 2, the first adhesive layer located on the first surface of the first battery cell 1a extends at least to half the width of the overlapping region, and the width direction of the overlapping region is consistent with the extending direction of the interconnect 2. In this case, the portion of the first adhesive layer 3a of the first battery cell extending into the overlapping region is relatively large, which can provide better support and buffering for the two battery cell portions in the overlapping region. When the first adhesive layer 3a of the first battery cell fills less than half its width of the overlapping region, the filling degree is relatively small, which can easily lead to some parts of the overlapping region of the two battery cells being thicker than others, resulting in stress concentration and cell cracking.

[0080] In some embodiments, as shown in FIG7, a first adhesive layer located on the first surface of the first battery cell 1a covers the edge of the first battery cell 1a along the extension direction of the interconnect 2. In this design, the first adhesive layer on the first surface of the first battery cell 1a extends to the non-overlapping area of ​​the second surface of the second battery cell 1b along the extension direction of the interconnect 2. During the lamination process, the edge of the first battery cell 1a is prone to exerting localized stress on the back surface of the second battery cell 1b under pressure, which can lead to microcracks appearing on the back surface of the second battery cell 1b from the edge of the first battery cell 1a. When the first adhesive layer 3a of the first battery cell adopts the design of this embodiment, it can be ensured that there is no direct hard contact between the edge of the first battery cell 1a and the back surface of the second battery cell 1b, with the first adhesive layer 3a of the first battery cell acting as a buffer, thus improving the problem of microcracks in the battery cell.

[0081] In some embodiments, as shown in FIG7, on the back side of the second battery cell 1b, along the extending direction of the interconnect 2, there are gaps between the first adhesive layer 3a, the second adhesive layer 5a, and the second adhesive layer 5b of the first battery cell. In other words, it can also be understood that gaps exist between the following ends: the end of the first adhesive layer 3a of the first battery cell near the second adhesive layer 5a of the second battery cell; the end of the second adhesive layer 5a of the first battery cell near the second adhesive layer 5a of the second battery cell; and the end of the second adhesive layer 5b of the second battery cell near both the first adhesive layer 3a and the second adhesive layer 5a of the first battery cell. In this case, the projections of the first adhesive layer 3a, the second adhesive layer 5a, and the second adhesive layer 5b of the second battery cell on their respective battery cells do not overlap at least partially. For stacked solar cells, on the back side of the second solar cell 1b, there are three adhesive layers: the first adhesive layer 3a of the first solar cell, the second adhesive layer 5a of the first solar cell, and the second adhesive layer 5b of the second solar cell. If the ends of all three adhesive layers overlap, or if the ends of two of the adhesive layers overlap, it will lead to an increase in the local thickness of the solar cell. This local thickening occurs near the overlapping area, which can easily lead to microcracks in the solar cell. This technical solution can more safely ensure the overlap between the three adhesive layers.

[0082] In some embodiments, as shown in FIG7, along the extension direction of the interconnect 2, the distance between the first adhesive layer on the first surface of the first battery cell 1a and the second pad 6b on the second surface of the second battery cell 1b adjacent to the first battery cell 1a is D, where D ≥ 3 mm. The interconnect 2 is fixed to the battery cell through the various pads on the battery cell. When the first adhesive layer 3a of the first battery cell extends to the back side of the second battery cell 1b, the first adhesive layer 3a of the first battery cell is located between the second surface of the second battery cell and the interconnect 2 (e.g., solder ribbon). When the first adhesive layer 3a of the first battery cell extends too far, the first adhesive layer 3a of the first battery cell is too close to the second pad 6b on the second surface (back side) of the second battery cell 1b, which increases the distance between the interconnect 2 and the second surface of the second battery cell 1b in the thickness direction, thus hindering the welding of the interconnect 2 to the second pad 6b. With this design, it can be ensured that the first adhesive layer 3a of the first battery cell can play a good buffering role and avoid the first adhesive layer 3a of the first battery cell affecting the welding reliability of the interconnect 2.

[0083] In some embodiments, a portion of the first adhesive layer located on the first surface of the first battery cell 1a, in the overlapping region, penetrates between the first battery cell 1a and the interconnect 2. In the overlapping region, due to the overlap of the battery cells, the pressure exerted by the interconnect 2 on the first battery cell 1a is greater than in the non-overlapping region, resulting in a greater risk of microcracks. Therefore, when this design is adopted, the hard contact between the interconnect 2 and the first battery cell 1a can be improved, reducing the risk of microcracks.

[0084] As shown in Figure 3, along the extension direction of the interconnect 2, the distance between the edge of the first adhesive layer 3 and the edge of the battery cell 1 is d1, where 0mm ≤ d1 ≤ 1mm. This results in a longer coverage length of the first adhesive layer 3 along the extension direction of the interconnect 2, reducing displacement and wobbling of the interconnect 2 and improving the welding reliability of the interconnect 2. For example, in some embodiments, d1 can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, or 1mm, or other suitable values.

[0085] As shown in Figure 5, along the extension direction of the interconnect 2, the distance between the edge of the second adhesive layer 5 and the edge of the battery cell 1 is d2, where 0mm ≤ d2 ≤ 5mm. This configuration allows for a suitable increase in the gap between the edge of the second adhesive layer 5 and the edge of the battery cell 1, while appropriately reducing the length of the second adhesive layer 5. This lowers the accuracy requirements for its installation and increases the installation speed. For example, in some embodiments, d2 can be 0.05mm, 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, or 5mm, or other suitable values.

[0086] As shown in Figure 3, on the first and second surfaces of the battery cell 1, along the direction perpendicular to the length of the interconnect 2, the distance by which the edge of the first adhesive layer 3 and / or the second adhesive layer 5 extends beyond the outermost interconnect 2 is d3, where d3 ≥ 3 mm, and the first adhesive layer 3 and / or the second adhesive layer 5 cannot extend beyond the edge of the battery cell 1. The outermost interconnect 2 refers to the interconnect 2 closest to the edge of the battery cell 1 along the direction perpendicular to the length of the interconnect 2. This technical solution ensures that the outermost interconnect 2 has a sufficiently wide first adhesive layer 3 or second adhesive layer 5 to bond with the battery cell 1, and also ensures that all interconnects 2 on the surface of the battery cell 1 are covered by the first adhesive layer 3 or the second adhesive layer 5, thereby reducing the problem of the first adhesive layer 3 and the second adhesive layer 5 lifting in this direction. In some embodiments, d3 can be 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, 5 mm, 5.2 mm, 5.5 mm, 5.8 mm, or 6 mm or other suitable values.

[0087] As shown in Figures 3 and 5, along the direction perpendicular to the length of the interconnect 2, the distance between the edge of the first adhesive layer 3 and / or the second adhesive layer 5 and the edge of the battery cell 1 is d4, where d4 ≥ 1 mm. This technical solution provides a suitable gap between the first adhesive layer 3 or the second adhesive layer 5 and the edge of the battery cell 1. This gap allows for continuous identification of the relative position between the battery cell 1 and the first adhesive layer 3 or the second adhesive layer 5 during the welding of the interconnect 2, preventing positional deviations and improving product yield. For example, in some embodiments, d4 can be 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, or 5 mm, or other suitable values.

[0088] In some embodiments, as shown in Figures 3 and 4, along a direction perpendicular to the length of the interconnect 2, the first surface includes adjacent first and second regions. Compared to the second region, the first region is located closer to the edge of the first surface, parallel to the plane of the interconnect 2. The first adhesive layer 3 covers the second region but not the first region, and an encapsulating film 4 covers the first region. Using this technical solution, during the encapsulation process, part of the encapsulating film is bonded to the first adhesive layer, and part is bonded to the first region on the battery cell, which can improve the fixing reliability between the encapsulating film and the battery cell.

[0089] As shown in Figure 5, the second surface includes a third region and a fourth region surrounding the third region. The second adhesive layer 5 covers the third region but not the fourth region, and the fourth region is covered with an encapsulating film 4. Using this technical solution, for the battery cell 1, the encapsulating film 4 is fixedly bonded to the periphery of the battery cell 1 and to the second adhesive layer 5 in the center, which can improve the fixing reliability between the battery cell 1, the encapsulating film 4, and the second adhesive layer 5.

[0090] In other embodiments, the first adhesive layer 3 and the second adhesive layer 5 can be made of the same or different materials. When the materials of the first adhesive layer 3 and the second adhesive layer 5 are different, depending on the actual application scenario, the first adhesive layer 3 or the second adhesive layer 5 can be made of a lower-cost material, thereby reducing the manufacturing cost of the photovoltaic module. For example, in some embodiments, the material of the second adhesive layer can be EVA (Ethylene Vinyl Acetate Copolymer), and the material of the first adhesive layer can be POE (Poly Olefin Elastomer), PEP (Phosphoenolpyruvate), or other suitable materials or an encapsulating film containing POE. When the materials of the first adhesive layer 3 and the second adhesive layer 5 are the same, depending on the actual application scenario, the first adhesive layer 3 and the second adhesive layer 5 can be made of EVA, POE, PEP, or other suitable materials.

[0091] As shown in Figure 6, the photovoltaic module also includes an encapsulating film 4 located on the side of the first adhesive layer 3 and / or the second adhesive layer 5 facing away from the solar cell 1. The encapsulating film 4 can protect the solar cell 1 from external water, oxygen, and other substances that could corrode it.

[0092] In practical applications, PID (Potential Induced Degradation) failure mainly occurs on the light-facing side of the photovoltaic module. Therefore, the first adhesive layer 3 and / or the encapsulating film 4 on the side of the first adhesive layer 3 facing away from the solar cell 1 can include an anti-PID material. The anti-PID material has non-polar molecules with saturated bonds, which can effectively prevent the PID phenomenon. For example, in some embodiments, the first adhesive layer 3 contains an anti-PID material, or the encapsulating film 4 on the outside of the first adhesive layer 3 contains an anti-PID material, or both the first adhesive layer 3 and the encapsulating film 4 on its outside contain anti-PID materials. Specifically, the anti-PID material can be any commercially available material.

[0093] The first adhesive layer 3 and / or the encapsulating film 4 on the side of the first adhesive layer 3 facing away from the battery cell 1 may include a non-polar material. For example, in some embodiments, the material contained in the encapsulating film does not contain polar groups. In this way, the first surface side of the battery cell, that is, the light-facing side, can have better resistance to PID, heat aging, and ultraviolet radiation.

[0094] In some embodiments, the first adhesive layer 3 and / or the encapsulation film 4 on the side of the first adhesive layer 3 facing away from the battery cell 1 includes POE. POE has nonpolar molecules with saturated bonds. Therefore, using POE to make the first adhesive layer 3 and / or the encapsulation film 4 on the side of the first adhesive layer 3 facing away from the battery cell 1 can effectively prevent PID phenomenon.

[0095] In some embodiments, the first adhesive layer 3 includes multiple stacked sub-adhesive layers, which are sequentially stacked along the thickness direction of the first adhesive layer 3. The thicknesses of the multiple sub-adhesive layers can be the same or different. At least one sub-adhesive layer is a POE layer, meaning that at least one sub-adhesive layer is made of POE. In this case, a complete POE layer covering the surface of the solar cell provides comprehensive anti-PID protection. Furthermore, in the module, no POE material is used in areas such as cell gaps, string gaps, and module edge gaps, thus reducing costs while maintaining anti-PID protection.

[0096] In some embodiments, the encapsulating film 4 on the side of the first adhesive layer 3 facing away from the battery cell 1 includes multiple stacked sub-adhesive layers. These sub-adhesive layers are sequentially stacked along the thickness direction of the encapsulating film 4, and their thicknesses can be the same or different. At least one sub-adhesive layer is a POE layer, meaning that at least one sub-adhesive layer is made of POE. POE has a high resistivity and a high barrier to moisture, and it is also resistant to ultraviolet radiation and does not easily yellow, ensuring that the first surface of the battery cell 1 does not experience a power reduction due to yellowing of the first adhesive layer 3.

[0097] Of course, the material of the first adhesive layer 3 may also include EPE (Expandable Polyethylene), which is not limited here.

[0098] Furthermore, the material of the second adhesive layer 5 may include EVA. EVA is a relatively inexpensive material, which can reduce processing costs, and EVA has better adhesion to the backing plate. The second adhesive layer 5 may also include multiple stacked sub-adhesive layers, which are sequentially stacked along the thickness direction of the second adhesive layer 5.

[0099] In some embodiments, the degree of crosslinking of the first adhesive layer 3 and the second adhesive layer 5 can be the same or different. If the degree of crosslinking of the first adhesive layer 3 and the second adhesive layer 5 is too low, the first adhesive layer 3 or the second adhesive layer 5 may flow between the interconnect 2 and the battery cell 1, affecting the welding effect between the battery cell 1 and the interconnect 2 and causing a poor weld. In view of the above, in this embodiment, the degree of crosslinking of both the first adhesive layer 3 and the second adhesive layer 5 is greater than or equal to 60% and less than or equal to 96% to improve the fixing reliability of the first and second adhesive layers to the battery cell.

[0100] In some embodiments, the degree of crosslinking of the first adhesive layer 3 is 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, or 96%. The degree of crosslinking of the second adhesive layer 5 is 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, or 96%.

[0101] In some embodiments, when the degree of crosslinking of the first adhesive layer 3 is different from that of the second adhesive layer 5, the degree of crosslinking of the first adhesive layer 3 is less than that of the second adhesive layer 5. When the first adhesive layer 3 includes an anti-PID material, the material flowability of the first adhesive layer 3 is poor. When the degree of crosslinking of the first adhesive layer 3 is smaller than that of the second adhesive layer 5, both can provide more balanced fixation performance and mechanical strength, thereby improving the adhesion performance and mechanical strength to the front and back sides of the battery cell 1.

[0102] In some embodiments, the difference between the crosslinking degree of the first adhesive layer 3 and the crosslinking degree of the second adhesive layer 5 is between 2% and 25%. For example, in some embodiments, the difference between the crosslinking degree of the first adhesive layer 3 and the crosslinking degree of the second adhesive layer 5 is 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25% or other suitable values. In this case, the difference in the crosslinking degree of the first adhesive layer 3 and the second adhesive layer 5 is appropriate, and the requirements for lamination temperature are more consistent, which can simplify the process and improve the manufacturing efficiency and yield of photovoltaic modules.

[0103] In some embodiments, the water vapor transmission rate of the first adhesive layer 3 is lower than that of the second adhesive layer 5. During the service life of the photovoltaic module, the front side of the photovoltaic module and the cells, that is, the side with the first adhesive layer 3, is more severely affected by water vapor erosion than the back side. Therefore, when the water vapor transmission rate of the first adhesive layer 3 is lower, it can provide a better water vapor barrier effect for the photovoltaic module compared to the second adhesive layer 5, thereby providing a better water vapor barrier effect at a lower cost.

[0104] As shown in Figure 6, during the lamination process, the first adhesive layer 3 and the second adhesive layer 5 are bonded to the side and top surfaces of the interconnect 2, meaning that the first adhesive layer 3 and the second adhesive layer 5 cover the side and top surfaces of the interconnect 2. The thickness of the first adhesive layer 3 at position A is less than the thickness of the first adhesive layer 3 at position B, and / or, the thickness of the second adhesive layer 5 at position A is less than the thickness of the second adhesive layer 5 at position B. Here, position A corresponds to the position of the interconnect 2, i.e., the position covering the interconnect 2, and position B is the position not covering the interconnect 2. In other words, the thickness of the first adhesive layer 3 at the position not covering the interconnect 2 is greater than the thickness of the first adhesive layer 3 at the position covering the interconnect 2, and the thickness of the second adhesive layer 5 at the position not covering the interconnect 2 is greater than the thickness of the second adhesive layer 5 at the position covering the interconnect 2. With this configuration, the additional adhesive layer at position B can fix and position the side of the interconnect 2, thus confining the interconnect 2 within the strip area defined by the adhesive layer at position B and reducing the distortion of the interconnect 2. Furthermore, the bonding of the first adhesive layer 3 and the second adhesive layer 5 to the side and top surfaces of the interconnect 2 enhances the reliability of the fixation of the interconnect 2. Even if there is no fixed connection between the bottom part of the interconnect 2 and the battery cell 1, the bonding of its top and side surfaces and the limiting effect of the adhesive layer at position B can greatly improve the alignment accuracy of the interconnect 2 and reduce positional deviation.

[0105] In some embodiments, the thickness difference between positions A and B of the first adhesive layer 3 is 0.03mm-0.05mm, and / or the thickness difference between positions A and B of the second adhesive layer 5 is 0.03mm-0.05mm. That is, the thickness difference between the position of the first adhesive layer 3 not covering the interconnect 2 and the position covering the interconnect 2 is 0.03mm-0.05mm, and / or the thickness difference between the position of the second adhesive layer 5 not covering the interconnect 2 and the position covering the interconnect 2 is 0.03mm-0.05mm. It should be understood that this thickness difference is related to the pressure of the lamination process. The higher the pressure, the thinner the thickness at position A, and the larger the difference; the lower the pressure, the thicker the thickness at position A, and the smaller the difference. When the thickness difference is within the above range, the thickness of the adhesive layer at the top of the interconnect 2 is relatively moderate, providing a good buffering and fixing effect. Optionally, the thickness difference between position A and position B of the first adhesive layer 3 is 0.03mm-0.04mm, and / or the thickness difference between position A and position B of the second adhesive layer 5 is 0.03mm-0.04mm.

[0106] In some embodiments, the thickness difference between position A and position B of the first adhesive layer 3 is 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, or 0.05 mm or other suitable values, and / or, the thickness difference between position A and position B of the second adhesive layer 5 is 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, or 0.05 mm or other suitable values.

[0107] As shown in Figure 6, in some embodiments, along the thickness direction of the battery cell 1, the height of the interconnect 2 is X, and the thickness of the portion of the first adhesive layer 3 and / or the second adhesive layer 5 not covering the interconnect 2 is h, where h = m1 * X, and 0.42 ≤ m1 ≤ 0.65. This configuration keeps the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 within a reasonable range, reducing air bubbles in the first and second adhesive layers 3 and 5, and preventing excessive thickness of the first and / or second adhesive layers 3 from affecting the light absorption efficiency of the battery cell 1.

[0108] For example, in some embodiments, when the height of the interconnect 2 is 190 μm, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 is 80 μm; when the height of the interconnect 2 is 184 μm, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 is 92 μm; when the height of the interconnect 2 is 160 μm, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 is 104 μm; when the height of the interconnect 2 is 204 μm, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 is 112 μm; and when the height of the interconnect 2 is 250 μm, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 is 120 μm.

[0109] In some embodiments, the basis weight of the first adhesive layer 3 and / or the second adhesive layer 5 is y1, where y1 = ρ1 * m * X, ρ1 is the density of the first adhesive layer 3 or the second adhesive layer 5, and the unit of ρ1 is g / m³. 3 The unit of X is m, and the unit of y1 is g / m. 2 This ensures the weight of the first adhesive layer 3 and / or the second adhesive layer 5, thereby guaranteeing a good encapsulation effect.

[0110] In some embodiments, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 is h, where 80 μm ≤ h ≤ 120 μm. That is, the thickness of the first adhesive layer 3 and / or the second adhesive layer 5 at the location not covering the interconnect 2 is within a reasonable range of 80 μm ≤ h ≤ 120 μm, which is suitable for most component products. This thickness of the first adhesive layer 3 and the second adhesive layer 5 can reduce the risk of adhesive layer bubbles and warping while also considering cost. In some embodiments, the thickness of the first adhesive layer 3 is 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, or 120 μm, or other suitable values. The thickness of the second adhesive layer 5 is 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, or 120 μm, or other suitable values.

[0111] In other embodiments, the photovoltaic module further includes an encapsulating film 4 disposed on the side of the first adhesive layer 3 facing away from the solar cell 1 and the side of the second adhesive layer 5 facing away from the solar cell 1. The thickness of the encapsulating film 4 is greater than or equal to 240 μm, that is, the thickness of the encapsulating film 4 at the location not covering the interconnect 2 is greater than or equal to 240 μm, to ensure the encapsulation effect. For example, in some embodiments, the thickness of the encapsulating film 4 is 240 μm, 245 μm, 250 μm, 255 μm, 260 μm or other suitable values.

[0112] In some embodiments, the weight of the encapsulating film 4 is y2, where y2 = [(1-m2)*X + d]*ρ2, d represents the minimum distance from the interconnect 2 to the inner side of the cover plate of the photovoltaic module, X is the height of the interconnect 2, and ρ2 is the density of the encapsulating film, 0.4 ≤ m2 ≤ 0.6. The unit of ρ2 is g / m³. 3 The unit of X is m, and the unit of y2 is g / m. 2 With this configuration, for interconnecting components 2 at a certain height, the basis weight of the encapsulating film of the photovoltaic module satisfies the above formula, thus providing sufficient moisture barrier effect and support function.

[0113] As shown in Figure 6, the photovoltaic module also includes an encapsulating film 4 disposed on the side of the first adhesive layer 3 facing away from the solar cell 1 and the side of the second adhesive layer 5 facing away from the solar cell 1. The total thickness of the first adhesive layer 3 and the encapsulating film 4 at position A is less than the total thickness at position B. The total thickness of the second adhesive layer 5 and the encapsulating film at position A is less than the total thickness at position B. Position A corresponds to the position of the interconnect 2, i.e., the position covering the interconnect 2, while position B is the position not covering the interconnect 2. With this arrangement, positions B of the first adhesive layer 3 and the second adhesive layer 5, as well as the portion of the encapsulating film 4 at position B, are all located on the side of the interconnect 2. On the side of the interconnect 2, the lower part has the first adhesive layer 3 or the second adhesive layer 5, and the upper part has the encapsulating film 4. At this point, the entire side of the interconnect 2 is bonded, fixed, and limited, thereby improving the fixing effect of the interconnect 2 and reducing the risk of the interconnect 2 shifting.

[0114] Furthermore, this application also provides a photovoltaic system comprising any of the aforementioned photovoltaic modules. The beneficial effects of the photovoltaic module provided in this application compared to the prior art can be analyzed with reference to the beneficial effects of solar cells, and will not be repeated here.

[0115] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0116] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. Photovoltaic modules, including: A battery cell having opposing first and second surfaces; Multiple interconnecting elements are used to connect multiple battery cells in series; multiple interconnecting elements are arranged at intervals on the first surface of the battery cell and multiple interconnecting elements are arranged at intervals on the second surface of the battery cell. A first adhesive layer is laid on the first surface of the battery cell, and the first adhesive layer is located on the side of the interconnect on the first surface away from the battery cell. The second adhesive layer is laid on the second surface of the battery cell, and the second adhesive layer is located on the side of the interconnect on the second surface away from the battery cell. The peel force between the second adhesive layer and the second surface is greater than the peel force between the first adhesive layer and the first surface.

2. The photovoltaic module according to claim 1, wherein, The difference between the peel force between the second adhesive layer and the second surface and the peel force between the first adhesive layer and the first surface is 0.2N-1.9N.

3. The photovoltaic module of claim 1, wherein, The first adhesive layer has a plurality of pressing points, and the second adhesive layer has a plurality of pressing points; and / or, the projections of the pressing points on the first adhesive layer and the pressing points on the second adhesive layer onto the solar cell do not at least partially overlap; And / or, the peel force between the second adhesive layer and the interconnect located on the second surface is greater than the peel force between the first adhesive layer and the interconnect located on the first surface.

4. The photovoltaic module of claim 1, wherein, Along the extension direction of the interconnect, the length of the first adhesive layer is greater than the length of the second adhesive layer.

5. The photovoltaic module of claim 1, wherein, Along the extending direction of the interconnect, the ratio of the length of the first adhesive layer to the length of the battery cell is greater than or equal to 0.9; and / or, Along the extension direction of the interconnect, the ratio of the length of the second adhesive layer to the length of the battery cell is greater than or equal to 0.

82.

6. The photovoltaic module of claim 1, wherein, The photovoltaic module includes multiple solar cells, which include a first solar cell and a second solar cell. An interconnect connects the front electrode of the first surface of the first solar cell and the back electrode of the second surface of the second solar cell. The first solar cell and the second solar cell overlap to form an overlapping area. Along the extension direction of the interconnect, the first adhesive layer on the first surface of the first battery cell extends at least to half the width of the overlapping region, the width direction of the overlapping region being consistent with the extension direction of the interconnect.

7. The photovoltaic module of claim 6, wherein, Along the extension direction of the interconnect, the first adhesive layer located on the first surface of the first battery cell extends to the non-overlapping area of ​​the second surface of the second battery cell.

8. The photovoltaic module of claim 6, wherein, On the back side of the second battery cell, along the extending direction of the interconnect, there are gaps between the first adhesive layer of the first battery cell, the second adhesive layer of the first battery cell, and the second adhesive layer of the second battery cell.

9. The photovoltaic module of claim 6, wherein, Along the extension direction of the interconnect, the distance between the first adhesive layer on the first surface of the first battery cell and the pad on the second surface of the second battery cell adjacent to the first battery cell is D, where D≥3mm.

10. The photovoltaic module of claim 6, wherein, A portion of the first adhesive layer located on the first surface of the first battery cell, in the overlapping region, penetrates between the first battery cell and the interconnect.

11. The photovoltaic module of claim 1, wherein, The projected area of ​​the first adhesive layer on the battery cell is larger than the projected area of ​​the second adhesive layer on the battery cell.

12. The photovoltaic module of claim 1, wherein, On the first and second surfaces of the battery cell, along a direction perpendicular to the length of the interconnect, the distance by which the edge of the first adhesive layer and / or the second adhesive layer extends beyond the outermost interconnect is d3, where d3 ≥ 3 mm; along a direction perpendicular to the length of the interconnect, the distance between the edge of the first adhesive layer and / or the second adhesive layer and the edge of the battery cell is d4, where d4 ≥ 1 mm.

13. The photovoltaic module of claim 1, wherein, Along a direction perpendicular to the length of the interconnect, the first surface includes an adjacent first region and a second region, wherein the first region is located closer to the edge of the first surface than the second region; the first adhesive layer covers the second region but does not cover the first region, and an encapsulating film is applied to the first region; And / or, the second surface includes a third region and a fourth region surrounding the third region, the second adhesive layer covers the third region but does not cover the fourth region, and the fourth region is covered with an encapsulating film.

14. The photovoltaic module of any of claims 1-13, wherein, The first adhesive layer and the second adhesive layer are made of different materials.

15. The photovoltaic module of any of claims 1-13, wherein, The first surface is the front side of the solar cell; the photovoltaic module also includes an encapsulating film located on the side of the first adhesive layer opposite to the solar cell; The first adhesive layer and / or the encapsulating film comprise an anti-PID material; and / or, The first adhesive layer and / or the encapsulating film contain non-polar materials.

16. The photovoltaic module of claim 15, wherein, The first adhesive layer and / or the encapsulating film comprise a polyolefin elastomer (POE); Alternatively, the first adhesive layer may comprise a plurality of stacked sub-adhesive layers, at least one of which is a POE layer; or, the encapsulating film may comprise a plurality of stacked sub-adhesive layers, at least one of which is a POE layer.

17. The photovoltaic module of any of claims 1-13, wherein, The degree of crosslinking of the first adhesive layer is different from that of the second adhesive layer; and / or, the degree of crosslinking of both the first adhesive layer and the second adhesive layer is greater than or equal to 60% and less than or equal to 96%.

18. The photovoltaic module of claim 17, wherein, The first surface is the front side of the battery cell; The degree of crosslinking of the first adhesive layer is less than that of the second adhesive layer; and / or, the difference between the degree of crosslinking of the first adhesive layer and the degree of crosslinking of the second adhesive layer is between 2% and 25%; and / or, the water vapor transmission rate of the first adhesive layer is less than that of the second adhesive layer.

19. The photovoltaic module of any of claims 1-13, wherein, Along the thickness direction of the battery cell, the height of the interconnect is X, and the thickness of the part of the first adhesive layer and / or the second adhesive layer that does not cover the interconnect is h, where h = m1 * X, 0.42 ≤ m1 ≤ 0.65; And / or, the thickness of the first adhesive layer and / or the second adhesive layer is h, 80μm≤h≤120μm; And / or, the basis weight of the first adhesive layer and / or the second adhesive layer is y1, y1 = ρ1 * m1 * X, where ρ1 is the density of the first adhesive layer or the second adhesive layer, and the unit of ρ1 is g / m³. 3 The unit of X is m, and the unit of y1 is g / m. 2 .

20. The photovoltaic module of any of claims 1-13, wherein, The photovoltaic module further includes an encapsulating film disposed on the side of the first adhesive layer opposite to the solar cell and the side of the second adhesive layer opposite to the solar cell; the thickness of the encapsulating film is greater than or equal to 240 μm; and / or, The weight of the encapsulating film is y2, where y2 = [(1-m2)*X + d]*ρ2, d represents the minimum distance from the interconnect to the inner side of the cover plate of the photovoltaic module, X is the height of the interconnect, and ρ2 is the density of the encapsulating film, 0.4 ≤ m2 ≤ 0.6, where the unit of ρ2 is g / m³. 3 The unit of X is m, and the unit of y2 is g / m. 2 .

21. The photovoltaic module of any of claims 1-13, wherein, The photovoltaic module further includes an encapsulating film disposed on the side of the first adhesive layer opposite to the solar cell and the side of the second adhesive layer opposite to the solar cell; The total thickness of the first adhesive layer and the encapsulating film at position A is less than the total thickness at position B; And / or, the total thickness of the second adhesive layer and the encapsulating film at position A is less than the total thickness at position B; Position A is the location where the interconnect is covered, and position B is the location where the interconnect is not covered.

22. The photovoltaic module of any of claims 1-13, wherein, The first adhesive layer and / or the second adhesive layer are bonded to the side and top surfaces of the interconnect; and / or, The thickness of the first adhesive layer at position A is less than the thickness of the first adhesive layer at position B; And / or, the thickness of the second adhesive layer at position A is less than the thickness of the second adhesive layer at position B; Position A is the location where the interconnect is covered, and position B is the location where the interconnect is not covered.

23. The photovoltaic module of claim 22, wherein, The thickness difference between position A and position B of the first adhesive layer is 0.03mm-0.05mm, and / or the thickness difference between position A and position B of the second adhesive layer is 0.03mm-0.05mm.

24. A photovoltaic system comprising a photovoltaic module according to any one of claims 1-23.

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