Photovoltaic module and manufacturing method thereof

Abstract

The invention relates to the technical field of photovoltaic modules, in particular to a photovoltaic module and a manufacturing method thereof. The manufacturing method comprises the following steps: manufacturing a battery piece unit: placing a buffer rubber piece on a battery piece to obtain the battery piece unit; the buffer rubber part is at least arranged on the first surface and is arranged along the edge of the first battery; the battery piece units are placed on a plurality of welding strips, the second faces face the welding strips, the welding strips are laid at intervals in the second direction, and the welding strips extend in the first direction; a plurality of welding strips are laid on the first faces of the battery piece units, the welding strips are laid at intervals in the second direction, and the welding strips extend in the first direction and are in lap joint with the buffer rubber parts; and welding: welding the battery piece with the plurality of welding strips laid on the first surface and the second surface. According to the invention, the welding strip is laid on the prefabricated battery piece unit, and the battery piece unit is welded with the laid welding strip, so that the high-efficiency manufacturing of the photovoltaic module is realized.

Description

Technical Field

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

[0002] During the manufacturing process of photovoltaic modules, when the solar cells are subjected to external forces (such as the pressure during lamination), microcracks are prone to occur, which in turn affects the performance and reliability of the photovoltaic modules. Summary of the Invention

[0003] This application discloses a photovoltaic module and its manufacturing method, which can solve the problem of microcracks in solar cells and achieve efficient manufacturing of photovoltaic modules.

[0004] To achieve the above objectives, in a first aspect, embodiments of this application disclose a method for manufacturing photovoltaic modules, including the following steps: Fabrication of a battery cell unit: A buffer adhesive is placed on a battery cell to obtain the battery cell unit; wherein, along the thickness direction of the battery cell, the battery cell has a first surface and a second surface disposed opposite to each other; along the first direction, the first surface has a first battery edge and a second battery edge disposed opposite to each other, and the buffer adhesive is at least disposed on the first surface and disposed along the first battery edge; Placing the battery cell unit: The battery cell unit is placed on multiple solder strips, with the second side facing the multiple solder strips, the multiple solder strips are laid at intervals along the second direction, and the solder strips extend along the first direction; wherein, the second direction intersects the first direction; Laying the welding strips: Multiple welding strips are laid on the first surface of the battery cell unit, the multiple welding strips are laid at intervals along the second direction, the welding strips extend along the first direction and overlap the buffer rubber component; Welding: Welding the battery cell to the multiple welding strips laid on the first surface and the second surface.

[0005] In a possible implementation of the first aspect, the steps of placing the battery cell unit and laying the solder ribbon are performed sequentially and repeatedly. Wherein, the second battery edge of the N+1th battery cell unit overlaps the buffer adhesive of the Nth battery cell unit, so that the plurality of battery cells are arranged along the first direction; along the first direction, two adjacent battery cells partially overlap. Multiple solder strips are connected between the second surface of the (N+1)th solar cell unit and the first surface of the Nth solar cell unit, where N is a positive integer.

[0006] In a possible implementation of the first aspect, in each of the battery cell units, along the first direction, a portion of the cushioning adhesive is partially laminated and bonded to the battery cell, and the remaining portion of the cushioning adhesive extends out of the battery cell.

[0007] In a possible implementation of the first aspect, in each of the battery cell units, the width of the overlapping portion of the buffer adhesive and the battery cell along the first direction is W1; The width of the buffer rubber component along the first direction is W2; satisfying the following relationship: (W2-W1) / W2=1 / 2~3 / 4.

[0008] In a possible implementation of the first aspect, W1 is 2 mm to 3 mm; and / or, The W2 is 4 mm to 6 mm.

[0009] In a possible implementation of the first aspect, in each of the battery cell units, the width of the overlapping portion of the buffer adhesive and the battery cell along the first direction is W1; Along the first direction, the width of the overlapping area of ​​two adjacent battery cells is W3, which satisfies the following relationship: W1 > W3.

[0010] In a possible implementation of the first aspect, along the first direction, the solder strip includes connected columnar segments and flat segments, the columnar segments having a circular, elliptical, or triangular cross-section, and the flat segments having opposing planes. In the step of laying the welding strip, along the first direction, the flat segment is placed corresponding to the buffer rubber component, one of the planes is in contact with the buffer rubber component, and the columnar segment is offset from the buffer rubber component.

[0011] In one possible implementation of the first aspect, the diameter of the columnar segment is 0.16 mm to 0.3 mm.

[0012] In a possible implementation of the first aspect, in each of the battery cell units, the buffer material is disposed only on the first surface and only along the edge of the first battery.

[0013] In one possible implementation of the first aspect, the initial pre-crosslinking degree of the buffer adhesive is 40% to 60%.

[0014] In a possible implementation of the first aspect, the step of fabricating the battery cell unit includes: The battery cell unit is heated to a temperature of 70°C to 90°C.

[0015] In one possible implementation of the first aspect, the buffer component is a buffer film with a thickness of 80 μm to 400 μm.

[0016] In one possible implementation of the first aspect, the length of the buffer material along the second direction is L1, and the length of the battery cell along the second direction is L2, satisfying the following relationship: L1≥L2; the second direction is perpendicular to the first direction.

[0017] In one possible implementation of the first aspect, L1 and L2 also satisfy the following relationship: L1-L2≤2mm.

[0018] In one possible implementation of the first aspect, the cushioning component includes at least one of EVA component, POE component, EVA-POE two-layer co-extruded component, and EVA-POE-EVA three-layer co-extruded component.

[0019] Secondly, embodiments of this application disclose a photovoltaic module, including: The battery cell has a first surface and a second surface disposed opposite to each other along its thickness direction; along the first direction, the first surface has a first battery edge and a second battery edge disposed opposite to each other. A cushioning element, the cushioning element being disposed on the first surface and at least along the edge of the first battery; and Multiple welding strips are connected to both the first and second surfaces. The welding strips are spaced apart along the second direction and extend along the first direction. The welding strips on the first surface overlap the cushioning rubber component. The first direction intersects the second direction.

[0020] In a possible implementation of the second aspect, the number of battery cells is multiple, the number of buffer rubber components is multiple strips, and the multiple battery cells are arranged along the first direction; Counting from the first direction, the edge of the second battery of the (N+1)th battery cell overlaps the edge of the first battery of the Nth battery cell, and the overlapping area is provided with the buffer material; along the thickness direction of the battery cell, the buffer material is at least partially disposed between two battery cells. Multiple solder strips are connected between the second side of the (N+1)th solar cell and the first side of the Nth solar cell, where N is a positive integer.

[0021] In a possible implementation of the second aspect, along the first direction, the width of the overlapping portion of the buffer adhesive and the individual battery cell is W1; The width of the cushioning rubber component along the first direction is W2; satisfying the following relationship: (W2-W1) / W2=1 / 2~3 / 4; and / or, Along the first direction, the width of the overlap area between two adjacent battery cells is W3, which satisfies the following relationship: W1 > W3; And / or, The length of the buffer rubber component along the second direction is L1, and the length of the battery cell along the second direction is L2, satisfying the following relationship: L1≥L2; the second direction is perpendicular to the first direction.

[0022] In a possible implementation of the second aspect, along the first direction, the solder strip includes connected columnar segments and flat segments; Along the first direction, the columnar segment is offset from the buffer rubber component, and the flat segment is correspondingly disposed to the buffer rubber component; The cross-section of the columnar segment is circular, elliptical, or triangular; Along the thickness direction of the battery cell, the flat segment has opposing planes, one of which is in contact with the cushioning adhesive and the other is in contact with the battery cell.

[0023] Compared with the prior art, the beneficial effects of this application include at least the following: The manufacturing method of this application solves the problem of microcracks in solar cells by prefabricating cell units and using a buffer component to prevent hard contact between the solder ribbon and the cell. Then, solder ribbon is laid on the prefabricated cell units, and the cell units are welded to the laid solder ribbon, thereby achieving efficient manufacturing of photovoltaic modules.

[0024] Specifically, this application prefabricates a battery cell unit by placing a buffer adhesive on the battery cell. Since the buffer adhesive is disposed along the edge of the first battery cell, and the solder ribbon on the battery cell unit for connection with the next battery cell unit overlaps on the buffer adhesive, the buffer adhesive helps to avoid hard contact between the solder ribbon and the edge sheet of the first battery cell, thereby reducing the problem of microcracks in the battery cell.

[0025] Based on this, this application lays and welds the solder strips on the prefabricated cell units, eliminating the need to apply glue after each solder strip laying, which simplifies the photovoltaic module manufacturing process and enables efficient photovoltaic module manufacturing. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a top view of a photovoltaic module; Figure 2 This is a flowchart illustrating a method for manufacturing a photovoltaic module as disclosed in an embodiment of this application. Figure 3 This is a perspective view of the battery cell unit disclosed in the embodiments of this application; Figure 4 for Figure 3 Top view; Figure 5 for Figure 4 The right view; Figure 6 for Figure 3 A schematic diagram showing the placement of solar cell units on multiple solder strips; Figure 7 for Figure 6 A schematic diagram showing the solar cell unit after the solder ribbon has been laid on it. Figure 8 for Figure 7 A schematic diagram showing the placement of the (N+1)th solar cell unit on the Nth solar cell unit; Figure 9 for Figure 8 A schematic diagram showing the N+1th solar cell unit after the solder ribbon has been laid on it; Figure 10 This is a schematic diagram of the structure of a photovoltaic module disclosed in an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 100. Photovoltaic module; 10. Cell unit; 1. Cell; 11. First side; 111. Edge of the first cell; 112. Edge of the second cell; 12. Second side; 2. Buffer material; 3. Welding strip; 31. Columnar segment; 32. Flat segment; 321. Plane; Z. Thickness direction of the cell; Y. First direction; X. Second direction; G. Spacing between cells. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] In this application, the terms "upper," "lower," "lateral," "longitudinal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0031] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0032] Furthermore, the terms "set up," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0033] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0034] See Figure 1 When the solar cells 1 of the photovoltaic module 100 are arranged in a spaced manner, there is a gap G between two adjacent solar cells 1. The gap G causes the proportion of the solar cell's light-receiving area to decrease, which in turn affects the power of the photovoltaic module 100.

[0035] In contrast, cascading is an effective technology for increasing the proportion of solar cells that receive sunlight. Cascading refers to arranging solar cells by overlapping them, connecting their edges end-to-end, thereby eliminating inter-cell spacing, increasing the proportion of sunlight-receiving area in the photovoltaic module, and ultimately improving the module's power output.

[0036] However, after lamination, the cells in tandem photovoltaic modules are highly susceptible to microcracks, which severely impacts the reliability and output power of the modules. This is because, to achieve electrical connections between the cells, the solder ribbon needs to pass through the cell overlap, resulting in hard contact between the solder ribbon and the cell at the overlap. During the lamination process, this hard contact exacerbates the stress at the cell overlap, leading to microcracks.

[0037] To address this issue, the inventors discovered that applying adhesive to the overlap area, which cures to form an adhesive layer, can effectively prevent hard contact between the solder ribbon and the solar cell, thereby reducing microcracks in the solar cell. However, the overlap area of ​​the solar cells is relatively narrow, requiring high precision in adhesive application. Adhesive overflow can contaminate the welding machine belt and affect the weld appearance. Furthermore, the shape of the adhesive is difficult to control during application; abnormal height and shape can negatively impact the anti-microcrack effect, or even have the opposite effect.

[0038] Based on the above analysis, this application provides a manufacturing method that, by prefabricating cell units, uses a buffer adhesive to prevent hard contact between the solder ribbon and the cell, thus solving the problem of microcracks in the cell. Furthermore, this application lays and welds the solder ribbon on the prefabricated cell units, eliminating the need to apply adhesive after each solder ribbon laying, which simplifies the photovoltaic module manufacturing process and enables efficient photovoltaic module manufacturing.

[0039] The technical solution of the present invention will now be described in conjunction with the embodiments and accompanying drawings.

[0040] Figure 2 This is a flowchart illustrating a method for manufacturing a photovoltaic module as disclosed in an embodiment of this application. Figure 3 This is a perspective view of the battery cell unit disclosed in the embodiments of this application; Figure 6 for Figure 3 A schematic diagram showing the placement of solar cell units on multiple solder strips; Figure 7 for Figure 6 This is a schematic diagram showing the solar cell unit after the solder ribbon has been laid on it. For ease of understanding, [the diagram is shown here]. Figure 2 , Figure 6 and Figure 7 In the diagram, the first surface 11 refers to the side of the battery cell 1 facing the paper, and the second surface 12 refers to the side of the battery cell 1 facing away from the paper.

[0041] Reference Figure 2 This application discloses a method for manufacturing a photovoltaic module, including the following steps: Fabricating solar cell units: such as Figures 3 to 5 As shown, a buffer adhesive 2 is placed on a battery cell 1 to obtain a battery cell unit 10; wherein, along the thickness direction Z of the battery cell, the battery cell 1 has a first surface 11 and a second surface 12 disposed opposite to each other; along the first direction Y, the first surface 11 has a first battery edge 111 and a second battery edge 112 disposed opposite to each other, and the buffer adhesive 2 is disposed at least on the first surface 11 and along the first battery edge 111; Placement of solar cell units: such as Figure 6As shown, the battery cell unit 10 is placed on multiple solder strips 3, with the second surface 12 facing the multiple solder strips 3. The multiple solder strips 3 are laid at intervals along the second direction X, and the solder strips 3 extend along the first direction Y; wherein the second direction X intersects the first direction Y. Laying welding strips: such as Figure 7 As shown, multiple welding strips 3 are laid on the first surface 11 of the battery cell unit 10. The multiple welding strips 3 are laid at intervals along the second direction X, and the welding strips 3 extend along the first direction Y and overlap on the buffer rubber part 2. Welding: Weld the battery cell 1 to multiple welding strips 3 laid on the first surface 11 and the second surface 12.

[0042] The beneficial effects of the manufacturing method described in this application will be explained below.

[0043] The manufacturing method of this application solves the problem of microcracks in the solar cell module 10 by prefabricating the cell unit 10 and using the buffer material 2 to avoid hard contact between the solder ribbon 3 and the cell 1. Then, the solder ribbon 3 is laid on the prefabricated cell unit 10, and the cell unit 10 is welded to the laid solder ribbon 3, thereby achieving efficient manufacturing of the photovoltaic module 100.

[0044] Specifically, this application prefabricates the battery cell unit 10 by placing a buffer adhesive 2 on the battery cell 1. Since the buffer adhesive 2 is disposed along the edge 111 of the first battery cell, and the solder ribbon 3 on the battery cell unit 10 for connection with the next battery cell unit 10 overlaps on the buffer adhesive 2, the buffer adhesive 2 helps to avoid hard contact between the solder ribbon 3 and the edge 111 of the first battery cell, thereby reducing the problem of microcracks in the battery cell 1.

[0045] Based on this, this application lays and welds the solder strips 3 on the prefabricated cell unit 10, eliminating the need to apply glue after each laying of the solder strips 3, which simplifies the manufacturing process of the photovoltaic module 100 and enables efficient manufacturing of the photovoltaic module 100.

[0046] In some embodiments, please refer to Figure 8 and Figure 9 The steps of placing the battery cells and laying the solder ribbon are performed sequentially and repeatedly.

[0047] In this configuration, the second battery edge 112 of the (N+1)th battery cell unit 10 overlaps with the buffer adhesive 2 of the Nth battery cell unit, so that the multiple battery cells 1 are arranged along the first direction Y. Along the first direction Y, two adjacent battery cells 1 partially overlap to form a stacked structure.

[0048] Multiple solder strips 3 connect the second surface 12 of the (N+1)th solar cell unit 10 to the first surface 11 of the Nth solar cell unit 10, so that the (N+1)th solar cell unit 10 is connected in series with the Nth solar cell unit 10, where N is a positive integer. N is, for example, 1, 2, 3, 4, or 5. In this embodiment, the solar cell units 10 are arranged in order of placement; for example, the second solar cell unit 10 is placed on the first solar cell unit 10, and the third solar cell unit 10 is placed on the second solar cell unit 10.

[0049] Specifically, the steps of placing the solar cell units, laying the welding ribbon, and welding can be completed in a stringing welding device. This stringing welding device includes a conveyor belt. Along the conveyor belt's transport direction, placement stations and welding stations are sequentially arranged on the conveyor belt. After the solar cell units 10 are manufactured, they are transferred to the placement station via suction cups. The steps of placing the solar cell units and laying the welding ribbon are performed sequentially in the placement station. Then, the conveyor belt performs a step-by-step transport of the solar cell units 10 with the welding ribbon 3 placed on them, conveying the solar cell units 10 and the welding ribbon to the welding station for welding.

[0050] For example, the type of solar cell can be a passivated contact solar cell (TOPCon cell), a heterojunction solar cell (HJT cell), or a perovskite cell. For these types of solar cells 1, the polarities of the grid electrodes on the first surface 11 and the second surface 12 are opposite. The second surface 12 of the (N+1)th solar cell unit 10 is connected to the first surface 11 of the Nth solar cell unit 10 in series by soldering.

[0051] This application allows for the prefabrication of the required number of solar cell units 10 during the manufacturing process. Since prefabricated solar cell units 10 are used, the steps of placing the solar cell units 10, laying the solder ribbon, and welding are performed sequentially to form one cycle. After multiple cycles, a battery string with a predetermined number of solar cells 1 can be obtained. Subsequently, the back glass panel, back adhesive film, battery string, front adhesive film, and front glass panel are sequentially stacked and fed into a laminator for lamination to obtain the photovoltaic module 100.

[0052] Compared to applying adhesive after laying the welding strip 3, this application attaches the buffer adhesive 2 to the battery cell 1 before laying the welding strip 3. The process of placing the buffer adhesive 2 is not carried out on the welding machine belt, which can avoid contaminating the welding machine belt and also helps to improve the welding appearance.

[0053] The battery cell unit in the manufacturing method of this application will be described in detail below.

[0054] In some embodiments, please refer to Figure 4 , Figure 5 and Figure 10In each battery cell unit 10, along the first direction Y, a portion of the buffer adhesive 2 is laminated and bonded to the battery cell 1, and the remaining portion of the buffer adhesive 2 extends out of the battery cell 1.

[0055] In this way, the overlapping portion of the buffer rubber component 2 and the battery cell 1 in each battery cell unit 10 provides a buffer for the placement of the next battery cell unit 10, making it easier for the next battery cell unit 10 to overlap on the buffer rubber component 2. The protruding portion of the buffer rubber component 2 can be placed under the next battery cell unit 10 to provide cushioning and further reduce microcracks.

[0056] Optionally, along the first direction Y, the width of the overlapping portion of the buffer rubber 2 and the battery cell 1 is W1, and the width of the buffer rubber 2 along the first direction Y is W2, satisfying the following relationship: (W2-W1) / W2=1 / 2~3 / 4.

[0057] This application controls the width ratio of the overlapping portion of the buffer adhesive 2 and the battery cell 1 to make the overlapping portion of the buffer adhesive 2 and the first surface 11 sufficiently wide, providing sufficient allowance for the placement and overlapping of the next battery cell unit 10.

[0058] Optionally, along the first direction Y, the width W1 of the overlapping portion of the buffer rubber 2 and the battery cell 1 is 2 mm to 3 mm, so that the overlapping portion of the buffer rubber 2 and the battery cell 1 is wide enough to provide sufficient allowance for the placement and overlapping of the next battery cell unit 10.

[0059] Optionally, the width W2 of the buffer element 2 along the first direction Y is 4 mm to 6 mm, for example, 4 mm, 5 mm, or 6 mm. This application controls the width of the buffer element 2 to ensure it is sufficiently wide to effectively protect the vulnerable area near the battery edge, while also preventing it from being too wide to avoid affecting the contact and welding of the solder strip 3 with the battery cell 1. It should be noted that in this application, the width of the buffer element 2 is much smaller than the width of the battery cell 1.

[0060] Reference Figure 10 Along the first direction Y, the width of the overlap area between two adjacent battery cells 1 is W3, satisfying the following relationship: W1 > W3. In this way, the overlapping portion of the buffer rubber 2 and the battery cell 1 is wide enough, thus providing sufficient redundancy for the overlapping placement of the battery cells 1.

[0061] Optionally, the width W3 of the overlapping area between two adjacent solar cells 1 is 0.16 mm to 0.3 mm.

[0062] Optionally, refer to the return Figure 4 and Figure 5The buffer element 2 is only provided on the first surface 11 and only along the edge 111 of the first cell. This arrangement of the buffer element 2 facilitates the efficient production of the cell unit 10 using automated equipment, and eliminates the need to flip the cell 1 when placing the buffer element 2. Furthermore, two overlapping cells 1 can share a single buffer element 2 for elastic cushioning, which helps to further reduce the material cost of the photovoltaic module 100.

[0063] Optionally, the initial pre-crosslinking degree of the buffer component 2 is 40% to 60%, for example, 40%, 45%, 50%, 55%, or 60%. In this application, "initial pre-crosslinking degree" refers to the pre-crosslinking degree of the buffer component 2 before it is placed onto the solar cell 1. Specifically, the initial pre-crosslinking degree of the buffer component 2 can be controlled by using a pre-crosslinking process (ultraviolet light, electron beam irradiation).

[0064] This application controls the initial pre-crosslinking degree of the buffer component 2 to be 40%~60% to ensure a sufficiently high pre-crosslinking degree. Since the flowability of the buffer component 2 is inversely proportional to the pre-crosslinking degree, the buffer component 2 with the aforementioned initial pre-crosslinking degree has lower flowability, and the deformation of the buffer component 2 under pressure is within a controllable range, thereby reducing the loss rate of the buffer component 2 during the lamination of the photovoltaic module 100. Furthermore, the initial pre-crosslinking degree of the buffer component 2 is not too high. Since the hardness of the buffer component 2 is positively correlated with the pre-crosslinking degree, the buffer component 2 with the aforementioned initial pre-crosslinking degree still has a certain degree of elasticity. During subsequent lamination, the buffer component 2 can play an elastic buffering role, further reducing the risk of microcracks in the solar cell 1.

[0065] Furthermore, the buffer adhesive 2 with the aforementioned initial pre-crosslinking degree has a certain degree of adhesion, and after being placed on the battery cell 1, it can be laminated and adhered to the battery cell 1, and will not easily fall off during subsequent turnover.

[0066] Further steps in fabricating the solar cell unit 10 include: The cell unit 10 is heated to a temperature of 70°C to 90°C, for example, 70°C, 80°C, or 90°C, so that the buffer material 2 is pre-fixed onto the cell 1. In this way, when the cell unit 10 is transferred to the placement station, the buffer material 2 can maintain its position and thus ensure that the buffer material 2 is located in the overlapping area of ​​the two cell 1s.

[0067] It is understandable that the heating process softens the buffer adhesive 2, allowing the buffer adhesive 2 with the aforementioned initial pre-crosslinking degree to adhere to the battery cell 1. The buffer adhesive 2 is in contact with the first surface 11, making the first surface 11 relatively flat, which helps to avoid stress concentration during the lamination process and thus reduces the risk of microcracks in the battery cell 1.

[0068] Optionally, the buffer component 2 is a buffer film. The thickness of the buffer film is 80 μm to 400 μm, for example, 80 μm, 160 μm, 240 μm, 320 μm or 400 μm.

[0069] This application controls the thickness of the buffer film to be between 80 μm and 400 μm, resulting in a thinner buffer film. A thinner buffer film helps reduce the height difference in the overlapping area of ​​the solar cells 1, thereby reducing the stress in the overlapping area of ​​the solar cells 1 during lamination, and further reducing the risk of microcracks in the solar cells 1 during lamination. Furthermore, the buffer film is not too thin; a sufficiently thick buffer film still provides good buffering performance.

[0070] In some embodiments, refer to Figure 4 and Figure 5 The length of the buffer rubber component 2 along the second direction X is L1, and the length of the battery cell 1 along the second direction X is L2, satisfying the following relationship: L1≥L2; the second direction X is perpendicular to the first direction Y. The buffer rubber component 2 is longer than or equal in length to the battery cell 1 so that the buffer rubber component 2 covers the edge 111 of the first battery cell, which helps to further reduce the risk of microcracks in the battery cell 1.

[0071] Furthermore, L1 and L2 also satisfy the following relationship: L1-L2≤2 mm. L1-L2 is, for example, 2 mm, 1.5 mm, 1 mm, 0.5 mm, or 0.1 mm. This application controls the length difference between the buffer adhesive 2 and the battery cell 1 to prevent the buffer adhesive 2 from protruding too much from the battery cell 1, which is beneficial for better adhesion between the front and back adhesive films and avoids abnormalities such as bubbles after encapsulation.

[0072] Optionally, the cushioning component 2 includes at least one of an EVA component, a POE component, an EVA-POE two-layer co-extruded component, and an EVA-POE-EVA three-layer co-extruded component. The EVA-POE two-layer co-extruded component includes a laminated EVA layer and a POE layer. The EVA-POE-EVA three-layer co-extruded component includes a first EVA layer, a POE layer, and a second EVA layer sequentially laminated. In this application, EVA is a polyethylene-polyvinyl acetate copolymer, and POE is a polyolefin elastomer.

[0073] The cushioning component 2, made of EVA and POE, has good elasticity and cushioning effect, which can effectively reduce the microcrack problem of the battery cell 1. The cushioning component 2 made of these materials also has good adhesion, light transmission and weather resistance.

[0074] The solder strip in the manufacturing method of this application will be described in detail below.

[0075] Furthermore, please refer to the following: Figures 7 to 10Along the first direction Y, the welding strip 3 includes a connected columnar segment 31 and a flat segment 32. Along the first direction Y, the columnar segment 31 is staggered from the buffer rubber component 2, and the flat segment 32 is correspondingly arranged with the buffer rubber component 2.

[0076] The columnar segment 31 has a circular or elliptical cross-section. Along the thickness direction Z of the solar cell, the flat segment 32 is stacked with the buffer material 2. The flat segment 32 has opposing planes 321, one of which is in contact with the buffer material 2. It can be understood that the other plane 321 of the flat segment 32 is in contact with the overlapping solar cell 1.

[0077] In short, the solder ribbon 3 is flattened at the corresponding position to the buffer adhesive 2 to form a flat segment 32. The cross-sectional shape of the flat segment 32 is, for example, square, capsule-shaped, or trapezoidal. During the lamination of the photovoltaic module 100, the two planes 321 of the flat segment 32 help to disperse pressure, thereby avoiding stress concentration and reducing the risk of microcracks in the cell 1. Furthermore, the portion of the solder ribbon 3 that is offset from the buffer adhesive 2 is a columnar segment 31. The columnar segment 31 with a circular or elliptical cross-section has no sharp edges, making it less likely to scratch the front or back adhesive film during encapsulation, which helps to improve the reliability of the photovoltaic module 100. Moreover, the columnar segment 31 with a circular or elliptical cross-section can also avoid stress concentration during lamination, which helps to further reduce the risk of microcracks in the cell 1.

[0078] Optionally, the diameter of the columnar segment 31 is 0.16 mm to 0.3 mm, for example, 0.16 mm, 0.2 mm, 0.25 mm, or 0.3 mm. By controlling the diameter of the columnar segment 31, this application achieves a lower resistivity because the resistivity of the solder ribbon 3 is inversely proportional to its cross-sectional area. Furthermore, the diameter of the columnar segment 31 is not excessively large, ensuring that the projected area of ​​the columnar segment 31 on the solar cell 1 remains small, thereby reducing the light-shielding area of ​​the solder ribbon 3 and improving the power output of the photovoltaic module 100. Additionally, a thinner columnar segment 31 helps avoid stress concentration on the solar cell 1 during lamination.

[0079] like Figure 9 and Figure 10 As shown in the figure, this application embodiment also discloses a photovoltaic module 100, including a battery cell 1, a buffer adhesive 2, and multiple welding strips 3.

[0080] Along the thickness direction Z of the battery cell, the battery cell 1 has a first surface 11 and a second surface 12 disposed opposite to each other; along the first direction Y, the first surface 11 has a first battery edge 111 and a second battery edge 112 disposed opposite to each other. A buffer member 2 is disposed on the first surface 11 and at least along the first battery edge 111. Multiple solder strips 3 are connected to both the first surface 11 and the second surface 12. The solder strips 3 are spaced apart along the second direction X and extend along the first direction Y. The solder strips 3 on the first surface 11 overlap the buffer member 2; wherein the first direction Y intersects the second direction X. The buffer member 2 can prevent hard contact between the solder strips 3 and the battery cell 1, thereby solving the problem of microcracks in the battery cell 1.

[0081] In some embodiments, the number of battery cells 1 is multiple, and the multiple battery cells 1 are arranged along the first direction Y.

[0082] In this configuration, counting from the first direction Y, the second battery edge 112 of the (N+1)th battery cell 1 overlaps the first battery edge 111 of the Nth battery cell 1, and a buffer adhesive 2 is correspondingly provided in the overlapping area. Along the thickness direction Z of the battery cell, the buffer adhesive 2 is at least partially disposed between two battery cells 1.

[0083] There are multiple solder strips 3 connecting the second surface 12 of the (N+1)th battery cell 1 to the first surface 11 of the Nth battery cell 1, where N is a positive integer.

[0084] In this way, each pair of adjacent battery cells 1 shares a buffer component 2, which helps to reduce the amount of buffer component 2 used and lower the material cost of the buffer component 2.

[0085] Optionally, refer to the return Figure 4 and Figure 5 The width of the overlap between the buffer component and the individual battery cell is W1, that is, the width of the overlap between the buffer component and the battery cell of the same battery cell unit during manufacturing is W1. The width of the buffer component along the first direction is W2; satisfying the following relationship: (W2 - W1) / W2 = 1 / 2 to 3 / 4. This application controls the width ratio of the overlap between the buffer component 2 and the battery cell 1 to ensure that the overlap between the buffer component 2 and the first surface 11 is sufficiently wide, providing ample allowance for the placement and overlap of the next battery cell unit 10.

[0086] Optionally, refer to Figure 10 Along the first direction, the width of the overlap area between two adjacent battery cells is W3, satisfying the following relationship: W1 > W3. In this way, the overlapping portion of the buffer rubber 2 and the battery cell 1 is wide enough, thus providing sufficient redundancy for the overlapping placement of the battery cells 1.

[0087] Optionally, refer to the return Figure 4 and Figure 5 The length of the buffer rubber component along the second direction is L1, and the length of the battery cell along the second direction is L2, satisfying the following relationship: L1≥L2; the second direction is perpendicular to the first direction. The buffer rubber component 2 is longer than or equal in length to the battery cell 1, so that the buffer rubber component 2 covers the edge 111 of the first battery cell, which helps to further reduce the risk of microcracks in the battery cell 1.

[0088] Please refer to the above as well. Figures 7 to 10 Along the first direction Y, the welding strip 3 includes a connected columnar segment 31 and a flat segment 32. Along the first direction Y, the columnar segment 31 is staggered from the buffer rubber component 2, and the flat segment 32 is correspondingly arranged with the buffer rubber component 2.

[0089] The cross-section of the columnar segment 31 is circular, elliptical, or triangular. The outer surface of the columnar segment 31 can reflect some light onto the surface of the solar cell 1, which helps to improve the conversion efficiency of the photovoltaic module 100.

[0090] Along the thickness direction Z of the solar cell, the flat segment 32 is stacked with the buffer material 2. The flat segment 32 has opposing planes 321, one of which is in contact with the buffer material 2. It can be understood that the other plane 321 of the flat segment 32 is in contact with the overlapping solar cell 1.

[0091] In short, the welding strip 3 is flattened at the corresponding position of the buffer rubber part 2 to form a flat segment 32. The two planes 321 of the flat segment 32 are conducive to pressure dispersion, thereby avoiding stress concentration and reducing the risk of microcracks in the battery cell 1.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for manufacturing a photovoltaic module, characterized in that, Includes the following steps: Fabrication of a battery cell unit: A buffer adhesive is placed on a battery cell to obtain the battery cell unit; wherein, along the thickness direction of the battery cell, the battery cell has a first surface and a second surface disposed opposite to each other; along the first direction, the first surface has a first battery edge and a second battery edge disposed opposite to each other, and the buffer adhesive is at least disposed on the first surface and disposed along the first battery edge; Placing the battery cell unit: The battery cell unit is placed on multiple solder strips, with the second side facing the multiple solder strips, the multiple solder strips are laid at intervals along a second direction, and the solder strips extend along a first direction; wherein, the second direction intersects the first direction; Laying the welding strips: Multiple welding strips are laid on the first surface of the battery cell unit, the multiple welding strips are laid at intervals along the second direction, the welding strips extend along the first direction and overlap the buffer rubber component; Welding: Welding the battery cell to the multiple welding strips laid on the first surface and the second surface.

2. The manufacturing method according to claim 1, characterized in that, The steps of placing the battery cell units and laying the solder ribbon are performed sequentially and repeatedly. Wherein, the second battery edge of the N+1th battery cell unit overlaps the buffer adhesive of the Nth battery cell unit, so that the plurality of battery cells are arranged along the first direction; along the first direction, two adjacent battery cells partially overlap. Multiple solder strips are connected between the second surface of the (N+1)th solar cell unit and the first surface of the Nth solar cell unit, where N is a positive integer.

3. The manufacturing method according to claim 2, characterized in that, In each of the battery cell units, along the first direction, a portion of the buffer adhesive is laminated and bonded to the battery cell, while the remaining portion of the buffer adhesive extends out of the battery cell.

4. The manufacturing method according to claim 3, characterized in that, In each of the battery cell units, along the first direction, the width of the overlapping portion of the buffer adhesive and the battery cell is W1; The width of the cushioning rubber component along the first direction is W2; The following relationship is satisfied: (W2-W1) / W2=1 / 2~3 / 4.

5. The manufacturing method according to claim 4, characterized in that, The W1 is 2 mm to 3 mm; and / or, The W2 is 4 mm to 6 mm.

6. The manufacturing method according to claim 3, characterized in that, In each of the battery cell units, along the first direction, the width of the overlapping portion of the buffer adhesive and the battery cell is W1; Along the first direction, the width of the overlapping area of ​​two adjacent battery cells is W3, which satisfies the following relationship: W1 > W3.

7. The manufacturing method according to claim 1, characterized in that, Along the first direction, the welding strip includes connected columnar segments and flat segments, the columnar segments having a circular, elliptical, or triangular cross-section, and the flat segments having opposing planes; In the step of laying the welding strip, along the first direction, the flat segment is placed corresponding to the buffer rubber component, one of the planes is in contact with the buffer rubber component, and the columnar segment is offset from the buffer rubber component.

8. The manufacturing method according to claim 7, characterized in that, The diameter of the columnar segment is 0.16 mm to 0.3 mm.

9. The manufacturing method according to claim 1, characterized in that, In each of the aforementioned battery cell units, the buffer material is disposed only on the first surface and only along the edge of the first battery cell.

10. The manufacturing method according to claim 1, characterized in that, The initial pre-crosslinking degree of the buffer rubber component is 40%~60%.

11. The manufacturing method according to claim 10, characterized in that, The steps for manufacturing the battery cell unit include: The battery cell unit is heated to a temperature of 70°C to 90°C to pre-fix the buffer rubber component onto the battery cell.

12. The manufacturing method according to claim 1, characterized in that, The buffer component is a buffer film with a thickness of 80 μm to 400 μm.

13. The manufacturing method according to claim 1, characterized in that, The length of the buffer rubber component along the second direction is L1, and the length of the battery cell along the second direction is L2, satisfying the following relationship: L1≥L2; the second direction is perpendicular to the first direction.

14. The manufacturing method according to claim 13, characterized in that, The L1 and L2 also satisfy the following relationship: L1-L2≤2 mm.

15. The manufacturing method according to any one of claims 1 to 14, characterized in that, The cushioning component includes at least one of EVA component, POE component, EVA-POE two-layer co-extruded component, and EVA-POE-EVA three-layer co-extruded component.

16. A photovoltaic module, characterized in that, include: The battery cell has a first surface and a second surface disposed opposite to each other along its thickness direction; along the first direction, the first surface has a first battery edge and a second battery edge disposed opposite to each other. A cushioning element, the cushioning element being disposed on the first surface and at least along the edge of the first battery; and Multiple welding strips are connected to both the first and second surfaces. The welding strips are spaced apart along the second direction and extend along the first direction. The welding strips on the first surface overlap the cushioning rubber component. The first direction intersects the second direction.

17. The photovoltaic module according to claim 16, characterized in that, The number of battery cells is multiple, the number of buffer rubber components is multiple strips, and the multiple battery cells are arranged along the first direction; Counting from the first direction, the edge of the second battery of the (N+1)th battery cell overlaps the edge of the first battery of the Nth battery cell, and the overlapping area is provided with the buffer material; along the thickness direction of the battery cell, the buffer material is at least partially disposed between two battery cells. Multiple solder strips are connected between the second side of the (N+1)th solar cell and the first side of the Nth solar cell, where N is a positive integer.

18. The photovoltaic module according to claim 16 or 17, characterized in that, Along the first direction, the width of the overlapping portion of the buffer adhesive and the individual battery cell is W1; The width of the cushioning rubber component along the first direction is W2; satisfying the following relationship: (W2-W1) / W2=1 / 2~3 / 4; and / or, Along the first direction, the width of the overlap area between two adjacent battery cells is W3, which satisfies the following relationship: W1 > W3; And / or, The length of the buffer rubber component along the second direction is L1, and the length of the battery cell along the second direction is L2, satisfying the following relationship: L1≥L2; the second direction is perpendicular to the first direction.

19. The photovoltaic module according to claim 16 or 17, characterized in that, Along the first direction, the welding strip includes connected columnar segments and flat segments; Along the first direction, the columnar segment is offset from the buffer rubber component, and the flat segment is correspondingly disposed to the buffer rubber component; The cross-section of the columnar segment is circular, elliptical, or triangular; Along the thickness direction of the battery cell, the flat segment has opposing planes, one of which is in contact with the cushioning adhesive and the other is in contact with the battery cell.

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