Solder strip, solar cell and photovoltaic module

Abstract

The utility model relates to the technical field of solar cells, and provides a solder strip, a solar cell and a photovoltaic module, the solder strip comprises a solder strip base body and a light conversion solder layer, the light conversion solder layer comprises a solder layer and light conversion agent particles, the solder layer is arranged on at least part of the surface of the solder strip base body, and the light conversion agent particles are dispersed in the solder layer. The light conversion agent particles are used for converting invisible light into visible light. By dispersing the light conversion agent particles in the solder layer, invisible light having irreversible damage to the cell substrate can be converted into visible light, for example, whether ultraviolet light directly irradiates the cell substrate or not is judged, a worker is reminded of timely treatment, and irreversible damage to the solar cell is reduced.

Description

Technical Field

[0001] This utility model relates to the field of solar cell technology, and in particular to a solder strip, a solar cell, and a photovoltaic module. Background Technology

[0002] The performance and lifespan of solar cells are affected by a variety of factors, among which degradation caused by ultraviolet (UV) light is a significant issue. To reduce the damage of UV light to solar cells, light transfer films are typically used to convert UV light into visible light, or cut-off films are used to block UV light. Light transfer films achieve the conversion of UV light to blue light by adding light conversion materials (light conversion agents) to conventional films, ensuring power while protecting the cells from UV damage; while cut-off films lead to a decrease in power. However, it is impossible to directly determine whether light transfer films and cut-off films have failed during use. If the failure of light transfer films and cut-off films goes undetected, UV light will directly irradiate the cell substrate, causing irreversible degradation of the solar cell. Utility Model Content

[0003] Based on this, this application provides a solder strip, solar cell, and photovoltaic module capable of indicating ultraviolet light irradiation onto a battery substrate.

[0004] In a first aspect, this application provides a solder strip, the solder strip comprising:

[0005] Welding strip substrate;

[0006] The light-transfer solder layer includes a solder layer and light-transfer particles. The solder layer is disposed on at least a portion of the surface of the solder ribbon substrate, and the light-transfer particles are dispersed within the solder layer. The light-transfer particles are used to convert non-visible light into visible light.

[0007] In some embodiments, the average particle size D50 of the phototransfer agent particles is 2 nm to 50 nm.

[0008] In some embodiments, the phototransfer agent particles include at least one of CdTe particles, CdSe particles, and ZnS particles.

[0009] In some embodiments, the width of the solder strip is 0.1 mm to 0.7 mm.

[0010] In some embodiments, the thickness of the solder strip is 0.1 mm to 0.7 mm.

[0011] In some embodiments, the thickness of the solder layer is 10 μm to 50 μm.

[0012] Secondly, this application provides a solar cell, the solar cell comprising:

[0013] A battery substrate having a light-facing surface and a back-light-facing surface disposed opposite to each other;

[0014] As described in the first aspect, the solder strip is at least disposed on the light-facing surface of the battery substrate, and the light transfer agent particles are at least dispersed in the solder layer on the side opposite to the battery substrate.

[0015] Thirdly, this application provides a photovoltaic module comprising a plurality of solar cells as described in the second aspect.

[0016] In some embodiments, the photovoltaic module further includes a panel layer and a first encapsulation layer, wherein the first encapsulation layer and the panel layer are sequentially stacked on the light-facing surface of the battery substrate in a direction away from the battery substrate.

[0017] In some embodiments, the first encapsulation layer includes at least one of a light conversion layer and a light cutoff layer; or, the first encapsulation layer includes a light conversion layer and a light cutoff layer, wherein the light cutoff layer and the light conversion layer are sequentially stacked on the light-facing surface in a direction away from the battery substrate.

[0018] In some embodiments, the photovoltaic module further includes a backsheet layer and a second encapsulation layer, wherein the second encapsulation layer and the backsheet layer are sequentially stacked on the back surface of the battery substrate in a direction away from the battery substrate.

[0019] Compared with traditional technologies, this utility model has at least the following beneficial effects:

[0020] This application incorporates light transfer particles in the solder layer of the solder strip, which can convert non-visible light into visible light. For example, it can convert ultraviolet light into visible light. When ultraviolet light does not irradiate the solder strip, the light transfer particles do not emit light; when ultraviolet light irradiates the solder strip, the light transfer particles emit visible light, thereby indicating the failure of the film layer in the solar cell, reminding the staff to take action, and effectively ensuring the photoelectric conversion efficiency of the solar cell. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of a welding strip provided in one embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a solar cell provided in one embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in one embodiment of the present invention.

[0024] Among them, 100-solder cell; 110-cell substrate; 120-solder ribbon; 121-solder ribbon substrate; 122-solder layer; 123-light transfer agent particles; 200-first encapsulation layer; 300-panel layer; 400-second encapsulation layer; 500-backsheet layer. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings, embodiments, and examples. These embodiments and examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The purpose of providing these embodiments and examples is to enable a more thorough and comprehensive understanding of the disclosure of the present invention. It should also be understood that the present invention can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present invention, and the equivalent forms obtained also fall within the protection scope of the present invention. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of the present invention. It should be understood that the present invention can be implemented without one or more of these details.

[0026] It should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," "fixed," and "set" 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 meaning of the above terms in this utility model according to the specific circumstances.

[0028] In this utility model, "optionally", "optionally", and "optional" mean that they are optional, that is, they are selected from either "with" or "without". If there are multiple "options" in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "option" is independent.

[0029] In this utility model, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0030] In this utility model, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0031] All documents mentioned in this utility model are incorporated herein by reference as if each document were individually incorporated by reference. Unless they conflict with the utility model's purpose and / or technical solution, all cited documents are incorporated herein by reference in their entirety and for all purposes. When citing documents in this utility model, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. Examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this utility model. It should be understood that when the cited content conflicts with the description in this utility model, this utility model shall prevail or be adapted to the description in this utility model.

[0032] In traditional technologies, solar cells utilize light-converting and light-blocking films to convert or block ultraviolet (UV) light from sunlight, preventing it from reaching the cell substrate and causing irreversible damage that could affect cell efficiency. A solar cell is only considered to have failed when its efficiency declines. However, the causes of efficiency decline include not only the failure of the light-converting and light-blocking films but also other factors. Therefore, traditional technologies struggle to determine whether UV light is reaching the cell substrate.

[0033] Based on this, the first aspect of this application provides a solder strip, such as Figure 1 As shown, the solder ribbon 120 includes a solder ribbon substrate 121 and a light transfer solder layer. The light transfer solder layer includes a solder layer 122 and light transfer particles 123. The solder layer 122 is disposed on at least a portion of the surface of the solder ribbon substrate 121, and the light transfer particles 123 are dispersed within the solder layer 122. The light transfer particles 123 are used to convert non-visible light into visible light.

[0034] This application incorporates light transfer particles 123 in the solder layer 122 of the solder ribbon 120. These particles convert non-visible light into visible light. For example, they can convert ultraviolet light into visible light. When ultraviolet light does not irradiate the solder ribbon 120, the light transfer particles 123 do not emit light; when ultraviolet light irradiates the solder ribbon 120, the particles emit visible light, thereby indicating a failure in the film layer of the solar cell 100 and prompting personnel to take corrective action, effectively ensuring the photoelectric conversion efficiency of the solar cell 100.

[0035] In some embodiments, the solder strip substrate 121 may be a copper substrate.

[0036] In some embodiments, the average particle size D50 of the light transfer agent particles 123 is 2nm to 50nm, for example, it can be 2nm, 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, or 50nm. The present application selects the average particle size D50 of the light transfer agent particles 123 as described above to improve the dispersibility of the light transfer agent particles 123, thereby improving the luminescence effect of the solder ribbon 120.

[0037] Understandably, the light-converting particles 123 only need to convert non-visible light into visible light. For example, they can convert ultraviolet light into visible red light or other conspicuous colors to serve as a warning. The light-converting particles 123 can be inorganic light-converting agents or quantum dot light-converting agents. The luminescence principle of quantum dot light-converting agents is as follows: Absorption process: When ultraviolet light shines on the quantum dot light-converting agent, its photon energy is absorbed by the quantum dot. This process involves electrons in the quantum dot transitioning from the valence band to the conduction band, forming excitons (i.e., electron-hole pairs). After absorbing ultraviolet light, the electrons in the quantum dot are excited to a higher energy level state, i.e., the excited state. In this state, the electron has higher energy. Emission process: Electrons in the excited state are unstable and tend to return to the ground state and release energy. In quantum dots, this energy conversion is usually achieved through the recombination of electrons and holes. When an electron transitions from the excited state back to the ground state, it releases a photon. Due to the energy level structure of quantum dots, the energies of these photons typically correspond to the wavelength range of red light (approximately 600 nm to 700 nm). Therefore, we can observe that quantum dot phototransfer agents convert ultraviolet light into red light.

[0038] In some embodiments, the light transfer agent particles 123 include at least one of CdTe particles, CdSe particles, and ZnS particles. The light transfer agent particles 123 of this application have high stability and are not affected during the fabrication processes of the solder ribbon 120 and the solar cell 100.

[0039] In some embodiments, the width of the solder strip 120 is 0.1mm to 0.7mm, for example, it can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm or 0.7mm.

[0040] In some embodiments, the thickness of the solder strip 120 is 0.1 mm to 0.7 mm, for example, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm or 0.7 mm.

[0041] In some embodiments, the mass content of phototransfer agent particles 123 in the phototransfer solder layer is 5% to 10%, for example, it can be 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, or 10.0%. The content of phototransfer agent particles 123 in the phototransfer solder layer selected above in this application makes the welding strength and resistivity of the solder ribbon 120 similar to that of conventional solder.

[0042] In some embodiments, the thickness of the solder layer 122 is 10μm to 50μm, for example, it can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm.

[0043] Understandably, the type of solder strip 120 can be selected according to the actual application requirements. This includes, but is not limited to, flat solder strips, round wire solder strips, or triangular solder strips. The width of a flat solder strip can be 0.10mm~0.30mm, the thickness can be 0.10mm~0.50mm, and the thickness of the solder layer 122 is 10μm~50μm. The diameter of a round wire solder strip can be 0.10mm~0.50mm, and the thickness of the solder layer 122 is 10μm~40μm. There are many design options for triangular solder strips, including pure triangular solder strips and segmented triangular solder strips. Taking a pure triangular solder strip as an example, the cross-section can be set as an equilateral triangle with a vertex angle of 60°~150°, the side length can be 0.20mm~0.70mm, and the thickness of the solder layer 122 is 10μm~50μm.

[0044] In some embodiments, the solder layer 122 completely covers the surface of the solder ribbon substrate 121.

[0045] The second aspect of this application provides a solar cell, such as... Figure 2 As shown, the solar cell 100 includes:

[0046] A battery substrate 110 has a light-facing surface and a back-light-facing surface disposed opposite to each other.

[0047] As described in the first aspect, the solder ribbon 120 is at least disposed on the light-facing surface of the battery substrate 110, and the light transfer agent particles 123 are at least dispersed in the solder layer 122 on the side opposite to the battery substrate 110.

[0048] In some embodiments, the battery substrate 110 may be a silicon battery substrate. For example, it may be an HJT battery substrate, a TOPcon battery substrate, or a PERC battery substrate.

[0049] A third aspect of this application provides a photovoltaic module, such as... Figure 3 As shown, the photovoltaic module includes a plurality of solar cells 100 as described in the second aspect.

[0050] In some embodiments, the photovoltaic module further includes a panel layer 300 and a first encapsulation layer 200, wherein the first encapsulation layer 200 and the panel layer 300 are sequentially stacked on the light-facing surface of the battery substrate 110 along a direction away from the battery substrate 110.

[0051] Optionally, the first encapsulation layer 200 includes at least one of a light conversion layer and a light cutoff layer.

[0052] In some embodiments, the first encapsulation layer 200 includes a light conversion layer or a light cutoff layer.

[0053] In some embodiments, the first encapsulation layer 200 includes a light conversion layer and a light cut-off layer, which are sequentially stacked on the light-facing surface of the battery substrate 110 along a direction away from the battery substrate 110.

[0054] In some embodiments, the panel layer 300 may be made of high-transmittance glass, light-converting glass, or light-cutoff glass, or may be made of a stack of high-transmittance glass, light-converting glass, and light-cutoff glass.

[0055] In some embodiments, the photovoltaic module further includes a backsheet layer 500 and a second encapsulation layer 400, wherein the second encapsulation layer 400 and the backsheet layer 500 are sequentially stacked on the back surface in a direction away from the battery substrate 110.

[0056] In some embodiments, the photovoltaic module further includes a frame (not shown). A laminate formed by the panel layer 300, the first encapsulation layer 200, the solar cell 100, the second encapsulation layer 400, and the backsheet layer 500 is disposed within the frame. The frame is used to improve the mechanical strength of the laminate.

[0057] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Experimental methods in the following embodiments that do not specify specific conditions should preferably refer to the guidelines given in this application, or may be performed according to experimental manuals or conventional conditions in the art, or according to the conditions recommended by the manufacturer, or with reference to experimental methods known in the art. It is understood that in the following embodiments, both the light conversion layer and the light cutoff layer can be conventional commercially available products.

[0058] Example 1

[0059] This embodiment provides a solder ribbon 120, including a solder ribbon substrate 121 made of copper, and a light transfer solder layer covering the outer surface of the solder ribbon substrate 121. The light transfer solder layer includes a Sn60Pb40 alloy solder layer 122 with a thickness of 15μm, and CdTe light transfer agent particles 123 with an average volume particle size D50 of 25nm dispersed in the solder layer 122. The mass content of the light transfer agent particles 123 in the light transfer solder layer is 7.5%. Further, the solder ribbon 120 is a round wire solder ribbon with a diameter of 0.26mm.

[0060] This embodiment also provides a solar cell 100, including a TOPCon cell substrate 110 based on an N-type silicon wafer and the aforementioned solder ribbon 120, wherein the solder ribbon 120 is disposed on the TOPCon cell substrate 110.

[0061] Comparative Example 1

[0062] This comparative example provides a solder strip 120, which differs from Example 1 in that the solder layer 122 does not contain phototransfer particles 123.

[0063] This comparative example also provides a solar cell 100, which differs from Example 1 in that the solder ribbon 120 is replaced with the solder ribbon 120 of Comparative Example 1 of this application.

[0064] Resistance tests were performed on the solder strip 120 in Example 1 and Comparative Example 1. The test methods included:

[0065] The resistivity of solder strip 120 was tested according to GB / T3048.2-2007. Five solder strips 120 of Example 1 and five solder strips 120 of Comparative Example 1 were tested respectively. The average resistivity of Example 1 and the average resistivity of Comparative Example 1 were obtained. The test results are shown in Table 1.

[0066] Table 1

[0067]

[0068] As can be seen from Table 1, the resistivity of the solder ribbon 120 of this application is similar to that of the conventional solder ribbon 120. The addition of phototransfer agent particles 123 to the solder layer 122 in this application has good stability and does not affect the resistivity of the solder ribbon 120.

[0069] The welding tensile strength of the solder strip 120 in the solar cell 100 of Example 1 and Comparative Example 1 was tested. The test method included:

[0070] Four solar cells 100 from Example 1 (two odd and two even cells) and four solar cells 100 from Comparative Example 1 (two odd and two even cells) were tested respectively to obtain the welding pull force of the solder strip 120 on the front side and the welding pull force of the solder strip 120 on the back side. The welding pull force was obtained according to ISO 7500-1:2015. The test results are shown in Table 2.

[0071] Table 2

[0072]

[0073] As can be seen from Table 2, the welding pull of the solder strip 120 in this application is similar to that of the traditional solder strip 120. The addition of phototransfer agent particles 123 to the solder layer 122 in this application does not affect the welding pull of the solder strip 120.

[0074] The solar cells 100 of Embodiment 1 and Comparative Example 1 were respectively assembled into a first photovoltaic module and a second photovoltaic module. The first photovoltaic module includes a light conversion layer and a panel layer 300 sequentially disposed on the surface of the solar cell 100. The light conversion layer uses a 420g / m² material. 2 The EPE encapsulant film and the panel layer 300 are made of high-transparency glass; it also includes an EVA layer and a backsheet layer 500 disposed on the side opposite to the solar cell 100 and the light conversion layer. The only difference between the second photovoltaic module and the first photovoltaic module is that the light conversion layer is replaced with a light cut-off layer, and the light cut-off layer uses 400g / m² material. 2 EPE film.

[0075] The performance of the first and second photovoltaic modules mentioned above was tested, and the test methods included:

[0076] Module power test: Ten first photovoltaic modules and ten second photovoltaic modules were tested using the IEC61215 standard to obtain the average module power. The test results are shown in Table 3.

[0077] Table 3

[0078]

[0079] As can be seen from Table 3, the average module power of the solar cell 100 with the solder strip 120 of this application is close to that of the solar cell 100 in the conventional technology.

[0080] The above-mentioned photovoltaic modules were subjected to reliability testing, and the testing methods included:

[0081] The first and second photovoltaic modules mentioned above were tested at 120 kWh / m². 2 240kWh / m 2 and 360kWh / m 2 The photovoltaic modules were irradiated under ultraviolet light to test the power degradation of the first and second photovoltaic modules and the appearance changes of the solder ribbon 120. The test results are shown in Table 4.

[0082] Table 4

[0083]

[0084] As can be seen from Table 4, this application can determine whether ultraviolet light has irradiated the battery substrate 110 by the color change of the appearance of the solder ribbon 120. When it is in a normal state, that is, when ultraviolet light has not irradiated the battery substrate 110, the solder ribbon 120 appears silver-white. When it is in a failed state, that is, when the light conversion film or the cutoff film fails, and ultraviolet light irradiates the battery substrate 110, the solder ribbon 120 appears red, so as to indicate to the staff to handle it.

[0085] In summary, the light transfer agent particles incorporated into the solder layer in this application have minimal impact on the resistivity and welding tensile strength of the solder strip, and also have a relatively small impact on the photoelectric conversion efficiency of the solar cell. This application incorporates light transfer agent particles into the solder layer of the solder strip, utilizing the ability of these particles to convert non-visible light into visible light. For example, it can convert ultraviolet light into visible light. When ultraviolet light does not irradiate the solder strip, the light transfer agent particles do not emit light; when ultraviolet light irradiates the solder strip, the light transfer agent particles emit visible light, thereby indicating film layer failure in the solar cell, alerting personnel to take corrective action, and effectively ensuring the photoelectric conversion efficiency of the solar cell.

[0086] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A solder strip, characterized in that The solder strip (120) comprises: a solder strip base (121); a light conversion solder layer, the light conversion solder layer comprising a solder layer (122) and light conversion agent particles (123), the solder layer (122) being arranged on at least part of the surface of the solder strip base (121), the light conversion agent particles (123) being dispersed in the solder layer (122), the light conversion agent particles (123) being used for converting non-visible light into visible light; the average particle size D50 of the light conversion agent particles (123) being 2nm-50nm.

2. The solder strip of claim 1, wherein, The light conversion agent particles (123) comprise at least one of CdTe particles, CdSe particles and ZnS particles.

3. The solder strip of claim 1, wherein, The width of the solder strip (120) is 0.1mm-0.7mm; and / or, The thickness of the solder strip (120) is 0.1mm-0.7mm.

4. The solder strip of any one of claims 1-3, wherein, The thickness of the solder layer (122) is 10μm-50μm.

5. A solar cell, characterized by The solar cell (100) comprises: a cell base (110) having a light-receiving surface and a back surface arranged oppositely; the solder strip (120) of any one of claims 1-4, the solder strip (120) being arranged on at least the light-receiving surface of the cell base (110), the light conversion agent particles (123) being dispersed in at least the solder layer (122) on the side away from the cell base (110).

6. A photovoltaic module, characterized by, The photovoltaic module comprises a plurality of solar cells (100) as claimed in claim 5.

7. The photovoltaic module of claim 6, wherein, The photovoltaic module further comprises a panel layer (300) and a first encapsulation layer (200), the first encapsulation layer (200) and the panel layer (300) being arranged in sequence on the light-receiving surface of the cell base (110) in a direction away from the cell base (110).

8. The photovoltaic module of claim 7, wherein, The first encapsulation layer (200) comprises a light conversion layer or a light cut-off layer; or, the first encapsulation layer (200) comprises a light conversion layer and a light cut-off layer, the light cut-off layer and the light conversion layer being arranged in sequence on the light-receiving surface of the cell base (110) in a direction away from the cell base (110).

9. A photovoltaic module as claimed in any of claims 6 to 8, wherein, The photovoltaic module further comprises a back panel layer (500) and a second encapsulation layer (400), the second encapsulation layer (400) and the back panel layer (500) being arranged in sequence on the back surface in a direction away from the cell base (110).

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