A photovoltaic panel

Abstract

The utility model belongs to photovoltaic technical field discloses a kind of photovoltaic panel, the photovoltaic panel includes back sheet, cell string and front plate which are sequentially laminated.The cell string includes multiple cell pieces and multiple solder strips, solder strip is welded on the surface of cell piece, so that multiple cell pieces are electrically connected, solder strip includes core body, the core body has welding surface welded with cell piece and non-welding surface deviating from cell piece, and flexible conductive nanometer material layer and protective coating are sequentially arranged on welding surface.After the connection of solder strip and cell piece, on the one hand, the welding point formed by solder strip is connected with cell piece, on the other hand, flexible conductive nanometer material layer and protective coating strengthen the connection of cell string, which is conducive to improving the connection reliability of cell piece and solder strip, can reduce the probability of hidden crack of cell string, ensure the power of photovoltaic panel, ensure the working reliability of photovoltaic panel, prolong the service life of photovoltaic panel.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a photovoltaic panel. Background Technology

[0002] Existing photovoltaic (PV) panels have a multi-layer structure, which typically includes a backsheet layer, an adhesive layer, solar cells, an adhesive layer, and a front sheet layer stacked sequentially. The front sheet layer is usually made of plastic sheets, such as PET (Polyethylene Terephthalate) sheets, while the backsheet layer is usually made of metal sheets or aluminum alloy sheets. PV panels generate heat during operation, and absorbing sunlight also raises their temperature. Due to the significant difference in thermal expansion coefficients between plastic and metal sheets, the deformation of the plastic and metal sheets will differ during operation. Larger deformation can lead to weak connections between the solar cells and the solder strips, resulting in incomplete soldering or even detachment. In severe cases, it can even cause microcracks in the solar cells.

[0003] During the operation of photovoltaic panels, mechanical deformation of the photovoltaic panels (such as module bending, vibration bending) can also cause the cells to detach from the solder ribbon. After multiple stress cycles, the solder layer of the solder ribbon will also develop cracks, thus causing the cells to fall off from the solder ribbon.

[0004] In summary, the above-mentioned reasons causing poor soldering or detachment between the solar cells and the solder ribbon will lead to a decrease in the power output of the photovoltaic panel, reduce its reliability, and shorten its lifespan. Utility Model Content

[0005] The purpose of this utility model is to provide a photovoltaic panel that can reduce the probability of microcracks appearing in the battery string during the operation of the photovoltaic panel, ensure the power of the photovoltaic panel, ensure the reliability of the photovoltaic panel, and extend the service life of the photovoltaic panel.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This utility model discloses a photovoltaic panel, including a back panel, a battery string, and a front panel stacked sequentially. The battery string includes multiple battery cells and multiple solder strips. The solder strips are welded to the surface of the battery cells to electrically connect the multiple battery cells. The solder strips include a core, which has a welding surface that is welded to the battery cells and a non-welding surface that is away from the battery cells. A flexible conductive nanomaterial layer and a protective coating are sequentially disposed on the welding surface.

[0008] In some embodiments, the flexible conductive nanomaterial layer is disposed around the core, and the protective coating is applied to the surface of the flexible conductive nanomaterial layer.

[0009] In some embodiments, the flexible conductive nanomaterial layer includes multi-walled carbon nanotubes with a diameter of 5 nm to 20 nm and a length of 5 μm to 20 μm.

[0010] In some embodiments, the thickness of the flexible conductive nanomaterial layer is 5 μm-10 μm.

[0011] In some embodiments, the core includes a tin-clad copper strip and a solder layer disposed on the surface of the tin-clad copper strip.

[0012] In some specific embodiments, the thickness of the tin-clad copper strip is 0.15mm-0.2mm; and / or the width of the tin-clad copper strip is 1.5mm-2mm.

[0013] In some specific embodiments, the thickness of the solder layer is 5μm-10μm.

[0014] In some embodiments, the thickness of the protective coating is 1 μm-2 μm.

[0015] In some embodiments, the backplate is bonded to the battery string via a lower encapsulation layer, the thickness of which is 0.4mm-0.6mm.

[0016] In some embodiments, the front panel is bonded to the battery string via an upper encapsulation layer, the thickness of which is 0.4mm-0.6mm.

[0017] The beneficial effects of this photovoltaic panel are as follows: The welding ribbon used in the battery string is made of a flexible conductive nanomaterial layer coated with a protective coating on the core. In actual operation, the flexible conductive nanomaterial layer can firmly connect with the battery string due to its flexibility and adhesion properties. After the welding ribbon is connected to the battery cell, on the one hand, the welding point formed by the welding ribbon connects with the battery cell, and on the other hand, the flexible conductive nanomaterial layer and the protective coating strengthen the connection between the battery string and the welding ribbon. This helps to improve the connection reliability between the battery cell and the welding ribbon, reduce the probability of microcracks in the battery string, ensure the power of the photovoltaic panel, ensure the working reliability of the photovoltaic panel, and extend the service life of the photovoltaic panel.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the photovoltaic panel according to an embodiment of the present invention;

[0020] Figure 2This is a schematic diagram of the battery string structure according to an embodiment of the present invention;

[0021] Figure 3 This is a cross-sectional schematic diagram of a welding strip according to an embodiment of the present utility model;

[0022] Figure 4 This is a cross-sectional schematic diagram of another welding strip according to an embodiment of the present utility model.

[0023] Figure label:

[0024] 100. Backplate; 200. Battery string; 210. Battery cell; 220. Solder ribbon; 221. Core; 2211. Solder-clad copper strip; 2212. Solder layer; 222. Flexible conductive nanomaterial layer; 223. Protective coating; 230. Solder joint; 300. Front panel; 400. Upper encapsulation layer; 500. Lower encapsulation layer. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0026] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 utility model based on the specific circumstances.

[0027] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0028] This utility model discloses a photovoltaic panel, with reference to... Figure 1 As shown, the photovoltaic panel includes a back panel 100, a battery string 200, and a front panel 300 stacked sequentially. (Reference) Figure 2As shown, the battery string 200 includes multiple battery cells 210 and multiple solder ribbons 220. The solder ribbons 220 are soldered to the surface of the battery cells 210 so that the multiple battery cells 210 are electrically connected. The solder ribbon 220 includes a core 221. The core 221 has a welding surface that is welded to the battery cells 210 and a non-welding surface that is away from the battery cells 210. A flexible conductive nanomaterial layer 222 and a protective coating 223 are sequentially disposed on the welding surface. It is understood that in the photovoltaic panel of this utility model, the welding ribbon 220 of the battery string 200 is made of a flexible conductive nanomaterial layer 222 and a protective coating 223 coated on the core 221. In actual operation, the flexible conductive nanomaterial layer 222 can be firmly connected to the battery string 200 due to its flexibility and adhesive properties. After the welding ribbon 220 is connected to the battery cell 210, on the one hand, the welding point 230 formed by the welding ribbon 220 is connected to the battery cell 210, and on the other hand, the flexible conductive nanomaterial layer 222 and the protective coating 223 strengthen the connection with the battery string 200. This helps to improve the connection reliability between the battery cell 210 and the welding ribbon 220, reduce the probability of microcracks in the battery string 200, ensure the power of the photovoltaic panel, ensure the working reliability of the photovoltaic panel, and extend the service life of the photovoltaic panel.

[0029] In some embodiments, a flexible conductive nanomaterial layer 222 is disposed around the core 221, and a protective coating 223 is coated on the surface of the flexible conductive nanomaterial layer 222. It is understood that the flexible conductive nanomaterial layer 222 covering the core 221 ensures that both the welded and non-welded surfaces of the core 221 are covered with the flexible conductive nanomaterial layer 222, thereby ensuring the connection strength between the flexible conductive nanomaterial layer 222 and the core 221 and reducing the probability of the flexible conductive nanomaterial layer 222 detaching, thus indirectly ensuring the connection strength between the solder ribbon 220 and the battery cell 210.

[0030] It should be noted that, in the actual assembly process, the solder ribbon 220 can be selected as a round solder ribbon, a triangular solder ribbon, or a flat solder ribbon according to actual needs, and the wrapping method of the flexible conductive nanomaterial layer 222 can be selected according to the shape of the solder ribbon 220.

[0031] In some embodiments, a flexible conductive nanomaterial layer 222 is formed in the region where the solder ribbon 220 and the battery cell 210 form a solder joint 230, and the flexible conductive nanomaterial layer 222 is not provided in other regions. This reduces the amount of flexible conductive nanomaterial layer 222 used, which helps to reduce the manufacturing cost of the solder ribbon 220.

[0032] In some embodiments, the flexible conductive nanomaterial layer 222 includes multi-walled carbon nanotubes. It is understood that multi-walled carbon nanotubes are concentric cylindrical nanomaterials formed by rolling up multiple layers of graphene sheets, with a fixed distance of approximately 0.34 nm between the layers. Multi-walled carbon nanotubes possess extremely high strength and toughness, with a Young's modulus reaching 5 TPa, a strength approximately 100 times that of steel, while having a weight density only 1 / 6 that of steel. The average Young's modulus of multi-walled carbon nanotubes is approximately 1.8 TPa, and the average flexural strength reaches 14.2 ± 10.8 GPa. Multi-walled carbon nanotubes exhibit good electrical conductivity and can be used to manufacture high-performance electrode materials, with an electron mobility reaching 10-10. 5 cm 2 / V·s, with conductivity superior to copper and a current carrying capacity as high as 10 9 A / cm 2 Multi-walled carbon nanotubes (MWCNTs) possess excellent thermal conductivity, with an axial thermal conductivity of approximately 3000 W / m·K - 6000 W / m·K, which is twice that of diamond and ten times that of copper. They also exhibit good chemical stability, resisting chemical corrosion. Using MWCNTs to fabricate the flexible conductive nanomaterial layer 222 strengthens the entire solder strip 220 and improves its thermal and electrical conductivity.

[0033] Optionally, the diameter of multi-walled carbon nanotubes can be 5nm-20nm, specifically 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, and 20nm. Of course, the diameter of multi-walled carbon nanotubes can also be other values ​​within the 5nm-20nm range, or a suitable value can be selected according to actual needs, and is not limited to the examples mentioned above.

[0034] Optionally, the length of the multi-walled carbon nanotubes is 5μm-20μm. The length of the multi-walled carbon nanotubes can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, or 20μm. Of course, the diameter of the multi-walled carbon nanotubes can also be other values ​​within the range of 5nm-20nm, or a suitable value can be selected according to actual needs, and is not limited to the examples mentioned above. It should be noted that if the length of the multi-walled carbon nanotubes covering the core 221 is greater than 20μm, multiple segments of multi-walled carbon nanotubes can be coated onto the core 221 along its length. Of course, in other embodiments of this invention, the flexible conductive nanomaterial layer 222 can also be selected according to actual needs, and is not limited to the multi-walled carbon nanotubes mentioned above.

[0035] In some embodiments, the thickness of the flexible conductive nanomaterial layer 222 is 5 μm-10 μm. Specifically, the thickness of the flexible conductive nanomaterial layer 222 can be 5 μm, 5.1 μm, 5.2 μm, 5.3 μm, 5.4 μm, 5.5 μm, 5.6 μm, 5.7 μm, 5.8 μm, 5.9 μm, 6 μm, 6.1 μm, 6.2 μm, 6.3 μm, 6.4 μm, 6.5 μm, 6.6 μm, 6.7 μm, 6.8 μm, 6.9 μm, 7 μm, 7.1 μm, 7.2 μm, 7.3 μm, etc. The thicknesses are 7.4 μm, 7.5 μm, 7.6 μm, 7.7 μm, 7.8 μm, 7.9 μm, 8 μm, 8.1 μm, 8.2 μm, 8.3 μm, 8.4 μm, 8.5 μm, 8.6 μm, 8.7 μm, 8.8 μm, 8.9 μm, 9 μm, 9.1 μm, 9.2 μm, 9.3 μm, 9.4 μm, 9.5 μm, 9.6 μm, 9.7 μm, 9.8 μm, 9.9 μm, and 10 μm. Of course, the thickness of the flexible conductive nanomaterial layer 222 can also be other values ​​in the range of 5 μm to 10 μm, or a suitable value can be selected according to actual needs, and is not limited to the examples listed above. It is understandable that if the thickness of the flexible conductive nanomaterial layer 222 is too large, it will increase the thickness of the solder ribbon 220, the thickness of the battery string 200, and thus the thickness of the entire photovoltaic panel. If the thickness of the flexible conductive nanomaterial layer 222 is too small, it will affect the reinforcing, thermal conductivity, and electrical conductivity of the flexible conductive nanomaterial layer 222. In this embodiment, the thickness of the flexible conductive nanomaterial layer 222 is controlled within the range of 5μm-10μm. This can control the thickness of the photovoltaic panel, which is beneficial to the thin and light design of the photovoltaic panel, while ensuring the reinforcing, thermal conductivity, and electrical conductivity of the flexible conductive nanomaterial layer 222. This ensures a reliable connection between the solder ribbon 220 and the battery cell 210, and ensures the working performance of the photovoltaic panel.

[0036] In some embodiments, the protective coating 223 is a transparent polyimide coating, which provides good protection without affecting the light utilization rate of the battery string 200.

[0037] In some embodiments, such as Figure 3 and Figure 4 As shown, the core 221 includes a tin-clad copper strip 2211 and a solder layer 2212 disposed on the surface of the tin-clad copper strip 2211. It is understood that the tin-clad copper strip 2211 has good conductivity, which can easily collect and guide electrons during the cell string 200 process, thus improving the overall performance of the photovoltaic panel. The solder layer 2212 is used to form solder joints 230 on the cell 210 during soldering, ensuring the connection stability between the entire solder strip 220 and the cell 210.

[0038] In some specific embodiments, the thickness of the solder-clad copper strip 2211 is 0.15mm-0.2mm. Specifically, the thickness of the solder-clad copper strip 2211 can be 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, or 0.20mm. Of course, other values ​​within the range of 0.15mm-0.2mm can also be selected according to actual needs, and are not limited to the examples mentioned above. It is understandable that if the thickness of the solder-clad copper strip 2211 is too small, the strength of the solder ribbon 220 will be reduced, making it prone to breakage. If the thickness of the solder-clad copper strip 2211 is too large, it will result in an excessively thick photovoltaic panel, which is not conducive to the thin and light design of the photovoltaic panel. Setting the thickness of the solder-clad copper strip 2211 to 0.15mm-0.2mm can ensure the strength of the solder ribbon 220, reduce the probability of solder ribbon 220 breakage, ensure the connection strength between the solder ribbon 220 and the solar cell 210, and control the thickness of the photovoltaic panel, which is conducive to the thin and light design of the photovoltaic panel.

[0039] In some specific embodiments, the width of the solder-clad copper strip 2211 is 1.5mm-2mm. Specifically, the width of the solder-clad copper strip 2211 can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm, or other values ​​within the range of 1.5mm-2mm, and is not limited to the examples mentioned above. It is understood that if the width of the solder-clad copper strip 2211 is too small, the strength of the solder ribbon 220 will decrease, making it prone to breakage. If the width of the solder-clad copper strip 2211 is too large, it will affect the effective working area of ​​the solar cell 210, reducing the power of the photovoltaic panel. Setting the width of the solder-clad copper strip 2211 to 1.5mm-2mm ensures the strength of the solder ribbon 220, reduces the probability of breakage, guarantees the connection strength between the solder ribbon 220 and the solar cell 210, and also helps to increase the effective working area of ​​the solar cell 210, ensuring the power of the photovoltaic panel.

[0040] In some specific embodiments, the thickness of the solder layer 2212 is 5μm-10μm. Specifically, the thickness of the solder layer 2212 is 5μm, 5.1μm, 5.2μm, 5.3μm, 5.4μm, 5.5μm, 5.6μm, 5.7μm, 5.8μm, 5.9μm, 6μm, 6.1μm, 6.2μm, 6.3μm, 6.4μm, 6.5μm, 6.6μm, 6.7μm, 6.8μm, 6.9μm, 7μm, 7.1μm, 7.2μm, 7.3μm, 7.4μm, 7.5μm, 7.6μm, 7.7μm. μm, 7.8μm, 7.9μm, 8μm, 8.1μm, 8.2μm, 8.3μm, 8.4μm, 8.5μm, 8.6μm, 8.7μm, 8.8μm, 8.9μm, 9μm, 9.1μm, 9.2μm, 9.3μm, 9.4μm, 9.5μm, 9.6μm, 9.7μm, 9.8μm, 9.9μm, 10μm. Of course, other values ​​in the range of 5μm-10μm can also be selected according to actual needs, and are not limited to the examples listed above. It is understandable that if the solder layer 2212 is too thick, it will increase the thickness of the solder ribbon 220, increase the thickness of the cell string 200, and thus increase the overall thickness of the photovoltaic panel. If the solder layer 2212 is too thin, it will affect the strength of the solder joint 230. In this embodiment, the thickness of the solder layer 2212 is controlled within the range of 5μm-10μm. This can control the thickness of the photovoltaic panel, which is beneficial to the thin and light design of the photovoltaic panel, and also ensure the strength of the solder joint 230, thereby ensuring a reliable connection between the solder ribbon 220 and the cell 210, and ensuring the working performance of the photovoltaic panel.

[0041] In some embodiments, the thickness of the protective coating 223 is 1μm-2μm. Specifically, the thickness of the protective coating 223 can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, or 2μm. Of course, other values ​​in the range of 1μm-2μm can also be selected according to actual needs, and are not limited to the examples mentioned above. It is understandable that if the thickness of the protective coating 223 is too large, it will increase the thickness of the solder ribbon 220, increase the thickness of the battery string 200, and thus increase the overall thickness of the photovoltaic panel. If the thickness of the protective coating 223 is too small, it will affect the protective effect of the protective coating 223 on the flexible conductive nanomaterial layer 222. In this embodiment, the thickness of the protective coating 223 is controlled within the range of 1μm-2μm. This can control the thickness of the photovoltaic panel, which is beneficial to the thin and light design of the photovoltaic panel, and ensure the protective effect of the flexible conductive nanomaterial layer 222, thereby ensuring a reliable connection between the solder ribbon 220 and the battery cell 210 and ensuring the working performance of the photovoltaic panel.

[0042] In some embodiments, the backplate 100 is bonded to the battery string 200 via a lower encapsulation layer 500, the thickness of which is 0.4mm-0.6mm.

[0043] In some specific embodiments, the lower encapsulation layer 500 is an EVA (ethylene-vinyl acetate copolymer) layer or a POE (polyolefin elastomer) layer.

[0044] In some embodiments, the front panel 300 is bonded to the battery string 200 via an upper encapsulation layer 400, the thickness of which is 0.4mm-0.6mm.

[0045] In some specific embodiments, the upper encapsulation layer 400 is an EVA (ethylene-vinyl acetate copolymer) layer or a POE (polyolefin elastomer) layer.

[0046] In some embodiments, the back plate 100 is an aluminum plate or a stainless steel plate, and the thickness of the back plate 100 is 0.2mm-0.5mm.

[0047] In some embodiments, the front panel 300 is a PET (Polyethylene Terephthalate) sheet with a thickness of 0.3mm-0.8mm.

[0048] Of course, in other embodiments of this utility model, the materials and thicknesses of the back plate 100, lower encapsulation layer 500, upper encapsulation layer 400 and front plate 300 can be selected according to the prior art and are not limited to the above description.

[0049] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A photovoltaic panel, characterized in that, The device includes a backplate, a battery string, and a front plate stacked sequentially. The battery string includes multiple battery cells and multiple solder strips. The solder strips are welded to the surface of the battery cells to electrically connect the multiple battery cells. The solder strips include a core with a welding surface that is welded to the battery cells and a non-welding surface that is away from the battery cells. A flexible conductive nanomaterial layer and a protective coating are sequentially disposed on the welding surface.

2. The photovoltaic panel according to claim 1, characterized in that, The flexible conductive nanomaterial layer is disposed around the core, and the protective coating is applied to the surface of the flexible conductive nanomaterial layer.

3. The photovoltaic panel according to claim 1, characterized in that, The flexible conductive nanomaterial layer includes multi-walled carbon nanotubes with a diameter of 5nm-20nm and a length of 5μm-20μm.

4. The photovoltaic panel according to claim 1, characterized in that, The thickness of the flexible conductive nanomaterial layer is 5μm-10μm.

5. The photovoltaic panel according to claim 1, characterized in that, The core includes a tin-clad copper strip and a solder layer disposed on the surface of the tin-clad copper strip.

6. The photovoltaic panel according to claim 5, characterized in that, The thickness of the tin-clad copper strip is 0.15mm-0.2mm; and / or the width of the tin-clad copper strip is 1.5mm-2mm.

7. The photovoltaic panel according to claim 5, characterized in that, The thickness of the solder layer is 5μm-10μm.

8. The photovoltaic panel according to claim 1, characterized in that, The thickness of the protective coating is 1μm-2μm.

9. The photovoltaic panel according to claim 1, characterized in that, The backplate is bonded to the battery string via a lower encapsulation layer, the thickness of which is 0.4mm-0.6mm.

10. The photovoltaic panel according to claim 1, characterized in that, The front panel is bonded to the battery string via an upper encapsulation layer, the thickness of which is 0.4mm-0.6mm.

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