Photovoltaic cell and photovoltaic panel
Patent Information
- Application Number
- CN202522553590.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-10-30
- Estimated Expiration
- 2035-12-01
AI Technical Summary
[0002]现有的光伏板为多层结构，多层结构通常包括依次层叠设置的背板层、粘胶层、电池片、粘胶层和前板层，前板层的材料通常为塑料板，例如PET（PolyethyleneTerephthalate，聚对苯二甲酸乙二醇酯）板等，背板层通常为金属板以及铝合金板等，光伏板在工作过程中会产生热量，且吸收太阳光也会使得光伏板的温度升高，由于塑料板和金属板的热膨胀系数差异较大，光伏板工作的过程中，塑料板和金属板的形变量会有一定差异，当形变量较大时会导致电池片与焊带之间的连接变得不牢靠，出现虚焊甚至脱焊的现象，严重时还会导致电池片出现隐裂，使得光伏板功率发生衰减，降低光伏板的工作可靠性，缩短光伏板的使用寿命
[0016]本实用新型的光伏电池片的有益效果：相比于现有技术中的银包铜焊带，银包铜焊带在光伏板发热时会膨胀，从而提升了焊带脱焊或者电池片隐裂的几率，本实用新型公开的光伏电池片的焊带与电池片焊接部分的焊接段采用记忆合金芯体和辅助涂层的复合结构，具有记忆合金芯体的焊接段在光伏板发热时，会主动收缩抵消光伏板的背板的膨胀应力，降低焊带出现虚焊、脱焊的几率，降低电池片出现隐裂的概率，保障光伏板功率，确保光伏板的工作可靠性，延长光伏板的使用寿命。
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Figure CN224924128U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic technology, and in particular to a photovoltaic cell and a photovoltaic panel. Background Technology
[0002] Existing photovoltaic (PV) panels have a multi-layer structure, typically consisting of a backsheet layer, an adhesive layer, solar cells, and a front sheet layer stacked sequentially. The front sheet layer is usually made of plastic, such as PET (Polyethylene Terephthalate), while the backsheet layer is typically made of metal or aluminum alloy. 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 differs during operation. Excessive deformation can lead to weak connections between the solar cells and solder strips, resulting in incomplete soldering or even detachment. In severe cases, it can cause microcracks in the solar cells, leading to power degradation, reduced reliability, and a shortened lifespan. Utility Model Content
[0003] One objective of this invention is to provide a photovoltaic cell that uses a memory-type solder ribbon. When the temperature of the photovoltaic panel rises, the solder ribbon actively contracts to offset the expansion stress of the back sheet of the photovoltaic panel, reducing the probability of poor soldering or desoldering of the solder ribbon, reducing the probability of microcracks in the cell, ensuring the power of the photovoltaic panel, ensuring the reliability of the photovoltaic panel, and extending the service life of the photovoltaic panel.
[0004] Another objective of this invention is to provide a photovoltaic panel that can reduce the probability of incomplete soldering or detachment of the solder strips of the solar cells, reduce the probability of microcracks in the solar cells, ensure the power output of the photovoltaic panel, ensure the reliability of the photovoltaic panel, and extend the service life of the photovoltaic panel.
[0005] To achieve this objective, the present invention adopts the following technical solution:
[0006] This utility model discloses a photovoltaic cell, comprising: a plurality of cells arranged sequentially along a first direction; a plurality of solder strips soldered to the cells to achieve electrical connection between the cells, the solder strips being arranged in multiple rows and columns along the first and second directions; wherein: the solder strips have a welding section that is welded to the cells to form a solder joint, the welding section comprising a shape memory alloy core and an auxiliary coating covering the shape memory alloy core.
[0007] In some embodiments, the cross-section of the shape memory alloy core is circular, and the diameter is 0.1mm-0.2mm.
[0008] In some embodiments, the shape memory alloy core is a nickel-titanium alloy core, and the auxiliary coating includes a nickel coating and a silver coating, wherein the nickel coating covers the surface of the nickel-titanium alloy core, and the silver coating covers the nickel coating.
[0009] In some specific embodiments, the thickness of the silver coating is 1μm-2μm.
[0010] In some specific embodiments, the thickness of the nickel coating is 0.2 μm-1 μm.
[0011] In some embodiments, along the first direction, the size L1 of the welded segment is 0.5mm-1.5mm, and the thickness of the welded segment is 0.1mm-0.3mm; along the second direction, the size L2 of the weld strip is 1.2mm-2.0mm.
[0012] In some embodiments, the pre-deformation amount of the shape memory alloy core is 3%-5%.
[0013] In some embodiments, the welding strip further includes a buffer section that abuts against the battery cell, the two ends of the buffer section being connected to the two welding sections respectively, and the buffer section being formed in a wavy structure.
[0014] In some specific embodiments, the wavelength of the wave-shaped structure is 2mm-5mm, and the wave height of the wave-shaped structure is 0.2mm-0.5mm.
[0015] This utility model also discloses a photovoltaic panel, comprising a back panel, a lower encapsulation layer, photovoltaic cells as described above, an upper encapsulation layer, and a front panel stacked in sequence.
[0016] The beneficial effects of this photovoltaic cell are as follows: Compared with the silver-clad copper solder strip in the prior art, which expands when the photovoltaic panel heats up, thus increasing the probability of solder strip detachment or microcracks in the cell, the photovoltaic cell disclosed in this invention uses a composite structure of shape memory alloy core and auxiliary coating for the welding section of the solder strip and the cell. The welding section with shape memory alloy core will actively contract to offset the expansion stress of the back sheet of the photovoltaic panel when the photovoltaic panel heats up, reducing the probability of solder strip failure and detachment, reducing the probability of microcracks in the cell, ensuring the power of the photovoltaic panel, ensuring the reliability of the photovoltaic panel, and extending the service life of the photovoltaic panel.
[0017] The beneficial effects of this photovoltaic panel are as follows: Because the photovoltaic cells of this photovoltaic panel use welding strips with welding sections composed of shape memory alloy cores and auxiliary coatings, when the photovoltaic panel heats up, the welding strips will actively shrink to offset the expansion stress of the back sheet of the photovoltaic panel, reducing the probability of incomplete welding or detachment of the welding strips, reducing the probability of microcracks in the cells, ensuring the power of the photovoltaic panel, ensuring the working reliability of the photovoltaic panel, and extending 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 cell according to an embodiment of the present invention;
[0020] Figure 2 This is a cross-sectional schematic diagram of the welding section of the welding strip in an embodiment of the present invention, along the plane containing the first and second directions.
[0021] Figure 3 This is a schematic diagram of the structure of the buffer section of the solder strip according to an embodiment of the present invention;
[0022] Figure 4 This is a cross-sectional schematic diagram of a photovoltaic panel according to an embodiment of the present invention.
[0023] Figure label:
[0024] 100, Photovoltaic cell; 110, Cell; 120, Welding strip; 121, Welding section; 1211, Shape memory alloy core; 1212, Auxiliary coating; 122, Buffer section; 130, Solder joint; 200, Backsheet; 300, Lower encapsulation layer; 400, Upper encapsulation layer; 500, Front panel. 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 cell 100, referenced... Figures 1-3 As shown, the photovoltaic cell 100 includes multiple cells 110 and multiple solder ribbons 120. The multiple cells 110 are arranged sequentially along a first direction, and the multiple solder ribbons 120 are soldered to the cells 110 to achieve electrical connection between the multiple cells 110. The multiple solder ribbons 120 are arranged in multiple rows and columns along the first direction and the second direction. Among them, the solder ribbons 120 have a welding segment 121 that is welded to the cells 110 to form a solder joint 130. The welding segment 121 includes a shape memory alloy core 1211 and an auxiliary coating 1212 covering the shape memory alloy core 1211. Understandably, compared to the silver-clad copper solder strips in the prior art, which expand when the photovoltaic panel heats up, the probability of solder strip detachment or microcracks in the cell increases. The welding section 121 of the welding part between the solder strip 120 and the cell 110 of the photovoltaic cell 100 disclosed in this utility model adopts a composite structure of shape memory alloy core 1211 and auxiliary coating 1212. When the photovoltaic panel heats up, the welding section 121 with shape memory alloy core 1211 will actively contract to offset the expansion stress of the back plate 200 of the photovoltaic panel, reduce the probability of solder strip 120 being poorly welded or detached, reduce the probability of microcracks in the cell 110, 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] It should be noted that the solder strip 120 requires shape memory training during the manufacturing process, as follows:
[0030] Step 1: Pre-stretch the 120mm welding strip at room temperature (25℃, martensitic state) to induce plastic deformation;
[0031] Step 2: Heat to 180℃ (above Af point, Austenite finish temperature, the end temperature of austenite phase transformation) and hold for 10 minutes to allow the shape memory alloy core 1211 of the solder strip 120 to form a "shrinkage to the original length" shape memory effect.
[0032] Step 3: Cool to room temperature, with the solder ribbon 120 remaining in a pre-stretched state (martensitic state), which is the "awaiting activation state". After these three steps, during the use of the solder ribbon 120, the photovoltaic panel will contract instead of expand when the temperature rises, thereby offsetting the expansion stress of the backsheet 200 of the photovoltaic panel, reducing the probability of poor soldering or desoldering of the solder ribbon 120, reducing the probability of microcracks in the solar cells 110, ensuring the power output of the photovoltaic panel, ensuring the reliability of the photovoltaic panel, and extending the service life of the photovoltaic panel.
[0033] In some embodiments, the cross-section of the shape memory alloy core 1211 is circular, and the diameter is 0.1mm-0.2mm.
[0034] Of course, in other embodiments of this utility model, the cross-sectional shape of the shape memory alloy core 1211 can also be a rectangular, elliptical, triangular or other structure, and the size can also be adjusted according to actual needs, and is not limited to the above limitations.
[0035] In some embodiments, reference Figure 2 As shown, the shape memory alloy core 1211 is a nickel-titanium alloy core. The auxiliary coating 1212 includes a nickel coating and a silver coating. The nickel coating covers the surface of the nickel-titanium alloy core, and the silver coating covers the nickel coating. It is understood that the silver coating improves weld wettability and conductivity, while the nickel coating prevents the silver coating from diffusing into the nickel-titanium alloy core. The auxiliary coating 1212, including both nickel and silver coatings, ensures the weldability and conductivity of the entire weld section 121 while also providing good protection for the nickel-titanium alloy core.
[0036] In some specific embodiments, the thickness of the silver coating is 1μm-2μm. Specifically, the thickness of the silver coating can be 1μm, 1.05μm, 1.1μm, 1.15μm, 1.2μm, 1.25μm, 1.3μm, 1.35μm, 1.4μm, 1.45μm, 1.5μm, 1.55μm, 1.6μm, 1.65μm, 1.7μm, 1.75μm, 1.8μm, 1.85μm, 1.9μm, 1.95μm, or 2μm, or other values within the range of 1μm-2μm, and is not limited to the examples mentioned above. Understandably, an excessively thick silver coating would increase the manufacturing cost of solder ribbon 120, while an insufficiently thick silver coating would result in poor welding and conductivity. Controlling the thickness of the silver coating within the range of 1μm-2μm can both control the manufacturing cost of solder ribbon 120 and ensure the welding and conductivity of the silver coating, thereby ensuring the welding performance of solder ribbon 120.
[0037] In some specific embodiments, the thickness of the nickel coating is 0.2 μm-1 μm. Specifically, the thickness of the nickel coating can be 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, 0.5 μm, 0.55 μm, 0.6 μm, 0.65 μm, 0.7 μm, 0.75 μm, 0.8 μm, 0.85 μm, 0.9 μm, 0.95 μm, or 1 μm. Of course, it can also be other values between 0.2 μm and 1 μm, and is not limited to the examples mentioned above. Understandably, an excessively thick nickel coating would increase the manufacturing cost of the solder strip 120, while an insufficiently thick nickel coating would result in poor isolation, allowing the silver coating to easily diffuse into the nickel-titanium alloy core. Controlling the nickel coating thickness within the range of 0.2μm-1μm effectively controls the manufacturing cost of the solder strip 120 while ensuring the isolation effect of the nickel coating, thereby preventing the silver coating from diffusing into the nickel-titanium alloy core. It should also be noted that in other embodiments of this invention, the specific materials of the shape memory alloy core 1211 and the auxiliary coating 1212 can be adjusted according to actual needs and are not limited to the above description.
[0038] In some embodiments, the dimension L1 of the welding segment 121 along the first direction is 0.5mm-1.5mm. Specifically, the dimension L1 of the welding segment 121 along the first direction can be 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1.0mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, or 1.5mm. Of course, other values within the range of 0.5mm-1.5mm can also be selected according to actual needs, and are not limited to the examples above. It is understandable that if the size L1 of the welding segment 121 along the first direction is too small, it will affect the welding reliability between the welding strip 120 and the battery cell 110. If the size L1 of the welding segment 121 along the first direction is too large, it will increase the manufacturing cost of the welding strip 120. Controlling the size L1 of the welding segment 121 along the first direction within the range of 0.5mm-1.5mm can both ensure the welding reliability between the welding strip 120 and the battery cell 110 and control the manufacturing cost of the welding strip 120.
[0039] In some embodiments, the thickness of the welded segment 121 is 0.1mm-0.3mm. Specifically, the thickness of the welded segment 121 can be 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, or 0.3mm. Of course, other values within the range of 0.1mm-0.3mm are also possible, and the thickness is not limited to the examples listed above. Understandably, if the thickness of the welding section 121 is too small, it will affect the welding reliability between the welding strip 120 and the battery cell 110. If the thickness of the welding section 121 is too large, it will increase the manufacturing cost of the welding strip 120. Controlling the thickness of the welding section 121 within the range of 0.1mm-0.3mm can both ensure the welding reliability between the welding strip 120 and the battery cell 110 and control the manufacturing cost of the welding strip 120.
[0040] In some embodiments, the dimension L2 of the solder strip 120 along the second direction is 1.2mm-2.0mm. Specifically, the dimension of the solder strip 120 along the second direction can be 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.9mm, 1.95mm, or 2.0mm. Of course, other values within the range of 1.2mm-2.0mm are also possible, and the dimensions are not limited to the examples mentioned above. Understandably, if the size L2 of the welding section 121 along the second direction is too small, it will affect the welding reliability between the welding strip 120 and the battery cell 110. If the size L2 of the welding section 121 along the second direction is too large, it will increase the manufacturing cost of the welding strip 120. Controlling the size L2 of the welding section 121 along the second direction within the range of 1.2mm-2.0mm can both ensure the welding reliability between the welding strip 120 and the battery cell 110 and control the manufacturing cost of the welding strip 120.
[0041] In some embodiments, the pre-deformation amount of the shape memory alloy core 1211 is 3%-5%. Specifically, it can be understood that the pre-deformation amount of the shape memory alloy core 1211 refers to the amount of plastic deformation applied to the shape memory alloy in the low-temperature martensitic state, which is a key parameter affecting its shape memory effect and superelasticity. Excessive or insufficient pre-deformation of the shape memory alloy core 1211 will affect its shape memory performance. In this embodiment, controlling the pre-deformation amount of the shape memory alloy core 1211 between 3% and 5% ensures its shape memory performance, thereby effectively offsetting the expansion stress of the photovoltaic panel's backsheet 200.
[0042] In some embodiments, such as Figure 3 As shown, the solder ribbon 120 also includes a buffer section 122 that abuts against the battery cell 110. Both ends of the buffer section 122 are connected to two solder sections 121, and the buffer section 122 forms a wavy structure. It can be understood that the buffer section 122 is the structure between the two solder joints 130. Setting the structure between the two solder joints 130 as a wavy structure can prevent contraction forces from directly acting on the solder joints 130, thereby further reducing the probability of the solder ribbon 120 experiencing poor soldering or even detachment.
[0043] In some specific embodiments, the wavelength of the wavy structure is 2mm-5mm. Specifically, the wavelength of the wavy structure can be 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, or 5mm. Of course, the wavelength of the wavy structure can also be other values within the range of 2mm-5mm, and is not limited to the examples mentioned above. Understandably, if the wavelength of the wavy structure is too small, the buffering effect will be worse, and the probability of the contraction force acting directly on the solder joint 130 will be greater. If the wavelength of the wavy structure is too long, it will increase the length of the buffer section 122, which, with the length of the solder strip 120 fixed, will shorten the length of the welding section 121, thereby reducing the welding reliability between the solder strip 120 and the photovoltaic cell 100. In this embodiment, the wavelength of the wavy structure is controlled within the range of 2 nm to 5 mm, which ensures both the buffering effect of the wavy structure and the length of the welding section 121, thus ensuring the welding reliability between the solder strip 120 and the photovoltaic cell 100. Of course, in other embodiments of this utility model, the wavelength of the wavy structure can be selected according to actual needs and is not limited to what has been described above.
[0044] In some specific embodiments, the wave height of the wavy structure is 0.2mm-0.5mm. Specifically, the structural wave height of the wavy structure can be 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, or 0.47mm. The wavelengths m, 0.48mm, 0.49mm, and 0.5mm are all acceptable. It's understood that the smaller the wave height of the wavy structure, the worse the buffering effect, and the greater the probability that the contraction force will directly act on the solder joint 130. Conversely, the larger the wave height, the lower the strength of the solder ribbon 120, thus reducing the welding reliability between the solder ribbon 120 and the photovoltaic cell 100. In this embodiment, the wavelength of the wavy structure is controlled within the range of 0.2nm-0.5mm, which ensures both the buffering effect of the wavy structure and the strength of the solder ribbon 120, thus ensuring the welding reliability between the solder ribbon 120 and the photovoltaic cell 100. Of course, in other embodiments of this invention, the wave height dimension of the wavy structure can be selected according to actual needs and is not limited to those described above.
[0045] like Figure 4 As shown, this utility model also discloses a photovoltaic panel, including a backplate 200, a lower encapsulation layer 300, a photovoltaic cell 100 (mentioned above), an upper encapsulation layer 400, and a front plate 500 stacked sequentially. Because the photovoltaic cell 100 of this photovoltaic panel uses a solder ribbon 120 with a welding section 121 composed of a shape memory alloy core 1211 and an auxiliary coating 1212, when the photovoltaic panel heats up, the solder ribbon 120 actively contracts to offset the expansion stress of the backplate 200 of the photovoltaic panel, reducing the probability of incomplete soldering or detachment of the solder ribbon 120, reducing the probability of microcracks in the cell 110, ensuring the power output of the photovoltaic panel, ensuring the operational reliability of the photovoltaic panel, and extending the service life of the photovoltaic panel.
[0046] Optionally, the back panel 200 can be made of aluminum or stainless steel, and its thickness is 0.2mm-0.5mm.
[0047] Optionally, the lower encapsulation layer 300 is an EVA (ethylene-vinyl acetate copolymer) layer or a POE (polyolefin elastomer) layer with a thickness of 0.4mm-0.6mm.
[0048] Optionally, the upper encapsulation layer 400 is an EVA (ethylene-vinyl acetate copolymer) layer or a POE (polyolefin elastomer) layer with a thickness of 0.4mm-0.6mm.
[0049] Optionally, the front panel 500 is made of PET (Polyethylene Terephthalate) sheet with a thickness of 0.3mm-0.8mm.
[0050] Of course, in other embodiments of this utility model, the materials and thicknesses of the backplate 200, lower encapsulation layer 300, upper encapsulation layer 400 and front plate 500 can be selected according to the prior art and are not limited to the above description.
[0051] 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.
[0052] 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 cell, characterized in that, include: Multiple battery cells, wherein the multiple battery cells are arranged sequentially along a first direction; Multiple solder strips are welded to the battery cells to achieve electrical connection between the multiple battery cells. The multiple solder strips are arranged in multiple rows and columns along the first direction and the second direction. The solder strips have welding sections that are welded to the battery cells to form solder joints. The welding sections include a shape memory alloy core and an auxiliary coating covering the shape memory alloy core.
2. The photovoltaic cell according to claim 1, characterized in that, The cross-section of the shape memory alloy core is circular, with a diameter of 0.1mm-0.2mm.
3. The photovoltaic cell according to claim 1, characterized in that, The shape memory alloy core is a nickel-titanium alloy core, and the auxiliary coating includes a nickel coating and a silver coating. The nickel coating covers the surface of the nickel-titanium alloy core, and the silver coating covers the nickel coating.
4. The photovoltaic cell according to claim 3, characterized in that, The thickness of the silver coating is 1μm-2μm.
5. The photovoltaic cell according to claim 3, characterized in that, The thickness of the nickel coating is 0.2μm-1μm.
6. The photovoltaic cell according to claim 1, characterized in that, Along the first direction, the size L1 of the welded segment is 0.5mm-1.5mm, and the thickness of the welded segment is 0.1mm-0.3mm. Along the second direction, the size L2 of the weld strip is 1.2mm-2.0mm.
7. The photovoltaic cell according to claim 1, characterized in that, The pre-deformation amount of the shape memory alloy core is 3%-5%.
8. The photovoltaic cell according to claim 1, characterized in that, The welding strip also includes a buffer section that abuts against the battery cell. The two ends of the buffer section are respectively connected to the two welding sections, and the buffer section is formed into a wavy structure.
9. The photovoltaic cell according to claim 8, characterized in that, The wavelength of the wave-shaped structure is 2mm-5mm, and the wave height is 0.2mm-0.5mm.
10. A photovoltaic panel, characterized in that, It includes a backsheet, a lower encapsulation layer, a photovoltaic cell as described in any one of claims 1-9, an upper encapsulation layer, and a front sheet, which are stacked in sequence.