All-black photovoltaic module and preparation method thereof

Abstract

The invention provides an all-black photovoltaic module and a preparation method thereof, and belongs to the technical field of solar cells, and the method comprises the steps: placing a cell string connected through a lamination technology on front tempered glass laid with a front light conversion film; connecting a black bus bar to the battery string according to design requirements, and welding the black bus bar and the black low-temperature welding strip at low temperature; laying a back light conversion film on the cell string, and laying back glass on the back light conversion film to form a laminated assembly; and laminating the laminated assembly in a laminating machine. According to the invention, the black low-temperature welding strip is mainly adopted, and the low-temperature welding strip is welded with the black bus bar, so that thermal stress damage to the battery piece caused by high-temperature welding can be avoided, and the electrical performance and long-term stability of the battery piece are improved; the low-temperature welding reduces the possibility that the electrode material of the battery piece and the silicon wafer interface send microstructure change, so that the photoelectric conversion efficiency can be improved; and low-temperature welding can also avoid the possibility of generating microcracks on the battery piece.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to a full-black photovoltaic component and a preparation method thereof. Background Art

[0002] As the global demand for clean energy continues to grow, the photovoltaic industry has developed rapidly. As the core unit of solar power generation, the performance improvement and cost reduction of photovoltaic modules have always been the focus of research. Due to its unique aesthetic appearance, all-black photovoltaic modules have broad market prospects in the fields of building facades, high-end distributed photovoltaic applications, etc.

[0003] Traditional photovoltaic modules face many challenges in achieving an all-black appearance. First, in terms of battery connection, conventional welding ribbons are usually silver or metallic in color, which makes it difficult to meet the appearance requirements of all-black modules. In addition, the traditional welding process often requires higher temperatures, which can easily cause thermal stress damage to the cells, affecting the electrical performance and long-term stability of the cells. For example, high-temperature welding may cause microstructural changes in the interface between the electrode material of the cell and the silicon wafer, increase the probability of carrier recombination, and thus reduce the photoelectric conversion efficiency. At the same time, higher welding temperatures may also cause microcracks in the cells. During long-term outdoor use, these microcracks will gradually expand, eventually causing a significant attenuation of the module power or even failure.

[0004] With the continuous advancement of photovoltaic technology, some new battery technologies such as 0BB (no main grid), TOPCon (tunneling oxide passivation contact), BC (back contact), HJT (heterojunction) and so on are gradually emerging. These battery technologies have significant potential in improving the efficiency of battery photoelectric conversion, but in the process of integrated application with all-black photovoltaic modules, the compatibility issues with other materials and components still need to be solved. For example, 0BB technology changes the connection method of battery cells, and it is necessary to develop matching low-temperature, black and electrical performance welding strips; high-efficiency battery technologies such as TOPCon put forward higher requirements on the optical performance and stability of packaging materials to give full play to their high-efficiency photoelectric conversion characteristics; BC and HJT technologies also face new challenges in connection and optical coupling with components such as busbars and glass due to their special battery structures.

[0005] In summary, existing photovoltaic modules have many shortcomings in terms of achieving all-black appearance, material optimization, battery technology integration, and long-term stability improvement. An innovative all-black photovoltaic module design is urgently needed to overcome these problems. Summary of the invention

[0006] The embodiment of the present invention provides an all-black photovoltaic module and a preparation method thereof, aiming to solve the problem that high-temperature welding of traditional all-black photovoltaic modules easily causes thermal stress damage to the battery cells, affecting the electrical performance and long-term stability of the battery cells, and high-temperature welding causes microstructural changes that reduce the photoelectric conversion efficiency, and microcracks in the battery cells lead to power failure of the photovoltaic module.

[0007] To achieve the above object, the technical solution adopted by the present invention is: to provide a method for preparing an all-black photovoltaic module, the method comprising: The cell strings connected by the lamination process are placed on the front tempered glass with the front light transfer film; Connect the black busbar to the battery string according to the design requirements, and solder the black busbar to the black low-temperature soldering tape at low temperature; Laying a back light transfer film on the battery string, and laying a back glass on the back light transfer film to form a laminated assembly; The laminated assembly is placed in a laminator for lamination.

[0008] In combination with the first aspect, in one achievable manner, a battery string connected by a lamination process is placed on a front tempered glass provided with a front light transfer film, and the lamination process includes: a lamination pressure of 0.1 - 0.3 MPa and a lamination temperature of 120 - 150°C.

[0009] In combination with the first aspect, in one achievable manner, in the low-temperature welding of the black bus ribbon and the black low-temperature solder ribbon, the welding temperature is 140-150° C., the welding time is 2-4 s, and the welding pressure is 0.1-0.2 MPa.

[0010] In combination with the first aspect, in an achievable manner, the composition of the black low-temperature solder strip includes a low-melting point alloy matrix and a black pigment; the low-melting point alloy matrix is ​​an alloy system composed of bismuth, tin, and indium; wherein, by mass percentage, the bismuth content is between 40% and 55%, the tin content is between 30% and 45%, and the indium content is between 5% and 20%; the melting point of the black low-temperature solder strip is 135°C - 155°C.

[0011] In combination with the first aspect, in one achievable manner, the black pigment is selected from nano-scale carbon materials or metal oxide materials, and the mass of the black pigment is 1% - 3% of the mass of the low-melting-point alloy matrix.

[0012] In combination with the first aspect, in one feasible manner, the front light transfer film and the back light transfer film are both composed of a matrix resin and a light conversion material; the matrix resin includes ethylene-vinyl acetate copolymer or polyolefin elastomer; the mass concentration of the light conversion material in the front light transfer film and the back light transfer film is 3% - 10%.

[0013] In combination with the first aspect, in one achievable manner, in the preparation of the light conversion film, a combination of ultrasonic dispersion and surface modifier-assisted dispersion is used to uniformly disperse the light conversion material in the matrix resin.

[0014] In conjunction with the first aspect, in one achievable manner, the process of placing the laminate assembly into a laminator for lamination includes: The lamination temperature is controlled at 140 - 160 °C, the pressure is controlled at 1 - 2 MPa, and the time is 10 - 20 min.

[0015] In combination with the first aspect, in one achievable manner, the back glass laid on the back light transfer film is glazed grid glass.

[0016] In the second aspect, an embodiment of the present invention further provides an all-black photovoltaic module, which is prepared by the preparation method of the all-black photovoltaic module, and includes a laminated assembly and an anti-dust accumulation frame installed around the laminated assembly, wherein the laminated assembly includes a battery string, and the front of the battery string is provided with a front light transfer film and a front tempered glass; the back of the battery string is provided with a back light transfer film and a back glass, and the back glass is a glazed grid glass; the battery string is welded by a black busbar and a black low-temperature welding strip; the anti-dust accumulation frame includes a supporting frame supported on the bottom of the laminated assembly and a side frame surrounded by the laminated assembly, and the upper end surface of the side frame is flush with the surface of the front tempered glass of the laminated assembly.

[0017] Compared with the prior art, the all-black photovoltaic module and the preparation method provided by the present invention have the following beneficial effects: (1) mainly adopting a black low-temperature solder strip and adopting low-temperature welding connection with a black busbar, which can avoid thermal stress damage to the battery cell caused by high-temperature welding, and improve the electrical performance and long-term stability of the battery cell; (2) Low-temperature welding reduces the possibility of microstructural changes in the interface between the electrode material of the battery cell and the silicon wafer, thereby improving the photoelectric conversion efficiency; (3) Low-temperature welding can also avoid the possibility of microcracks in the battery cell, and avoid the risk of failure of the photovoltaic module caused by the expansion of microcracks; (4) Low-temperature welding can improve the photoelectric conversion efficiency of the battery for 0BB busbar-free batteries, TOPCon tunneling oxide layer passivation contact batteries, BC back contact batteries and HJT heterojunction batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a full black photovoltaic module (a laminated module without a frame) provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a fully black photovoltaic module (package frame) provided in an embodiment of the present invention Figure 1 ; Figure 3 A schematic diagram of the structure of a fully black photovoltaic module (package frame) provided in an embodiment of the present invention Figure 2 ; Description of reference numerals: 1. Front tempered glass; 2. Black low-temperature solder tape; 3. Front light transfer film; 4. Back light transfer film; 5. Back glass; 6. Battery string; 7. Laminated assembly; 8. Anti-dust frame; 81. Side frame; 82. Support frame. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Please also read Figures 1 to 3 , the all-black photovoltaic module provided by the present invention is now described.

[0021] Embodiment 1, a method for preparing the all-black photovoltaic module, the method comprising: Step 1: placing the battery string 6 connected by the lamination process on the front tempered glass 1 with the front light transfer film 3; Step 2: Connect the black busbar to the battery string 6 according to the design requirements, and low-temperature weld the black busbar to the black low-temperature welding strip 2; Step 3: Lay a back light transfer film 4 on the battery string 6, and lay a back glass 5 on the back light transfer film 4 to form a laminated assembly 7; Step 4, placing the lamination assembly 7 into a laminator for lamination; Step 5: The laminated assembly 7 is sealed and fixed with a dust-proof frame 8, see Figure 2 and Figure 3 .

[0022] Compared with the prior art, the all-black photovoltaic module and the preparation method provided by the present invention have the following beneficial effects: (1) mainly adopting a black low-temperature solder strip 2 and adopting low-temperature welding connection with a black busbar, which can avoid thermal stress damage to the battery cell caused by high-temperature welding, and improve the electrical performance and long-term stability of the battery cell; (2) low-temperature welding reduces the possibility of microstructural changes between the electrode material of the battery cell and the silicon wafer interface, thereby improving the photoelectric conversion efficiency; (3) low-temperature welding can also avoid the possibility of microcracks in the battery cell, and avoid the risk of failure of the photovoltaic module caused by the expansion of microcracks; (4) low-temperature welding can improve the photoelectric conversion efficiency of the battery for 0BB busbar-free batteries, TOPCon tunneling oxide layer passivation contact batteries, BC back contact batteries and HJT heterojunction batteries.

[0023] Embodiment 2 See also Figures 1 to 3 The specific implementation steps of the overall assembly and packaging process of the all-black photovoltaic module provided by the present invention are as follows: Step 1, placing the battery string 6 connected by the lamination process on the front tempered glass 1 on which the front light transfer film 3 has been laid, ensuring that the battery string 6 is arranged neatly and keeps a distance of 10.5-12mm from the edge of the glass; Step 2: Connect the black busbar to the corresponding position of the battery string 6 according to the design requirements, and weld the black busbar to the black low-temperature solder strip 2. The welding process strictly controls parameters such as welding temperature, time and pressure. The welding temperature is 140-150°C, the welding time is 2-4 s, and the welding pressure is 0.1-0.2MPa to ensure reliable welding quality. Step 3: Lay a back light transfer film 4, such as POE, EPE or EVA, on the battery string 6 so that the light transfer film evenly covers the battery string 6; cover the back light transfer film 4 with a back glazed grid glass; Step 4: Place the assembled lamination assembly 7 into a laminator for lamination, with the lamination temperature controlled at 140-160°C, the pressure controlled at 1-2MPa, and the time being 10-20 min, so that each layer of material is tightly combined; Step 5: Install the laminated assembly 7 in the treated anti-dust frame 8, seal and fix it with the anti-dust frame 8 through high-strength black silica gel, install the junction box and perform electrical connection test to ensure that the electrical performance of the assembly is normal, and complete the preparation process of the entire all-black photovoltaic assembly. The anti-dust frame 8 is an aluminum frame or a steel frame.

[0024] The following is a detailed explanation of the various steps of the all-black photovoltaic module: In step 1, the battery string 6 connected by the lamination process is placed on the front tempered glass 1 with the front light transfer film 3. The lamination process is as follows: the number of main grid lines of the battery cell is set between 10 and 24, and the lamination process can be used for assembly. The lamination process can effectively reduce the gap between the battery cells, reduce the resistance loss, and increase the output power of the component. At the same time, the lamination structure helps to achieve a tighter arrangement of the battery cells in a limited space, and enhance the overall stability and mechanical strength of the component.

[0025] During the lamination process, the lamination pressure is precisely controlled between 0.1 - 0.3MPa and the lamination temperature is controlled between 120 - 150℃ to ensure that the connection between the battery cells is tight and without damage.

[0026] Specifically, the lamination pressures are 0.1 MPa, 0.2 MPa, 0.25 MPa, and 0.3 MPa, and the lamination temperatures are 120°C, 125°C, 130°C, 140°C, 142°C, and 150°C.

[0027] Preparation of the front tempered glass 1: The front tempered glass 1 can be made of anti-glare glass, and its glass substrate can be made of tempered glass with a thickness of 1.5-2.5mm. An anti-glare layer is formed on the surface of the tempered glass by chemical etching or coating process, and the microstructure of the anti-glare layer is an irregular micro-convex or micro-concave structure with a size of 1-10μm.

[0028] Front tempered glass 1 Anti-glare performance: Anti-glare glass can effectively reduce the reflection and glare of sunlight on the glass surface, improve the transmittance and uniformity of light, and allow more light to vertically enter the battery cells inside the module, thereby improving the photoelectric conversion efficiency. For example, compared with ordinary glass, anti-glare glass can increase the light transmittance of the module by 3% - 8%; at the same time, its black appearance is coordinated with the overall design of the all-black module, ensuring the beauty of the module.

[0029] In step 2, the black busbar is connected to the battery string 6 according to the design requirements, and the black busbar is low-temperature welded to the black low-temperature welding strip 2, including the preparation of the black low-temperature welding strip 2 and the low-temperature welding process.

[0030] The preparation process of the black low-temperature solder strip 2 is as follows: the black low-temperature solder strip 2 is mainly composed of a low-melting-point alloy matrix and a black pigment. The low-melting-point alloy matrix is ​​an alloy system composed of elements such as bismuth (Bi), tin (Sn), and indium (In), wherein, by mass percentage, the bismuth content is between 40% and 55%, the tin content is between 30% and 45%, and the indium content is between 5% and 20%. By accurately adjusting the proportion of each element, the melting point of the solder strip is controlled between 135°C and 155°C.

[0031] For example, the bismuth content is 40%, 45%, 50%, and 55%, the tin content is 30%, 35%, 40%, and 45%, the indium content is 5%, 8%, 10%, 12%, 15%, and 20%, and the melting point of the solder strip is 135°C, 140°C, 150°C, 152°C, and 155°C.

[0032] Black pigments are made of nano-scale carbon materials or special metal oxide pigments, such as carbon nanotubes or black copper oxide, which account for 1% - 3% of the mass of the low-melting-point alloy matrix.

[0033] The low-temperature welding process is as follows: Due to the low-temperature characteristics of the black low-temperature welding strip 2, the thermal damage to the battery cell can be effectively reduced during the welding process, and the risk of battery cell performance degradation caused by high temperature can be reduced. For example, when welding with various types of battery cells (such as 0BB, TOPCon, BC, HJT battery cells), reliable electrical connection can be achieved at a lower temperature (140℃ - 150℃) and a shorter time (2 - 4 seconds), and the electrical performance and mechanical strength of the battery cell after welding are maintained well.

[0034] The black low-temperature solder tape 2 is used to match the overall design of the all-black photovoltaic module appearance.

[0035] Since the traditional welding strip is not black and the welding temperature is high, the all-black photovoltaic module has poor aesthetics, and the high temperature damages the cell lattice and produces microcracks, increases carrier recombination, reduces the photoelectric conversion efficiency, and affects the long-term stability and life of the module. The present invention uses a black low-temperature welding strip 2 to solve the above problems caused by high-temperature welding.

[0036] The preparation process of black busbar is as follows: a composite ratio of conductive filler and black pigment is used. The conductive filler can be made of metal powder such as silver powder and copper powder, and mixed with black pigment in a certain mass ratio (such as 3:1 - 5:1). The black pigment is selected from pigments with good weather resistance and chemical stability, such as carbon black; it is prepared by extrusion molding process, with an extrusion temperature of 180-220℃ and a pressure of 2-4MPa, to ensure that the black appearance is maintained while achieving efficient current transmission.

[0037] Function and performance of black busbar: Black busbar plays an important role in collecting and transmitting current in the module. Its good conductivity ensures that the current can be efficiently transmitted from the battery cell to the external circuit. At the same time, the all-black appearance matches the overall black design of the module, reducing light reflection and scattering losses and improving the optical efficiency of the module; and its material formula and preparation process ensure stability and reliability during long-term outdoor use, and can withstand the test of different environmental conditions (such as high temperature, high humidity, ultraviolet radiation, etc.), and is not prone to discoloration, aging, decreased conductivity and other problems.

[0038] In step three, a back light transfer film 4 is laid on the battery string 6, and a back glass 5 is laid on the back light transfer film 4 to form a laminated assembly 7. The light transfer film is prepared as follows (the front light transfer film 3 is the same as the back light transfer film 4, and the name is only to distinguish its position in the battery string 6).

[0039] Preparation of light transfer film: mainly includes base resin and light conversion material. The base resin can be selected from ethylene-vinyl acetate copolymer (EVA) or polyolefin elastomer (POE), etc., which has good adhesion and weather resistance. The light conversion material uses fluorescent substances or quantum dot materials, such as phosphors containing rare earth elements or CdSe / ZnS quantum dots. The mass concentration of fluorescent substances or quantum dot materials in the light transfer film is 3% - 10%. Through dispersion processes, such as ultrasonic dispersion combined with surface modifier assisted dispersion, ensure that the light conversion material is evenly dispersed in the base resin to avoid agglomeration and ensure the uniformity of the optical properties of the light transfer film.

[0040] Performance of light transfer film: Light transfer film can absorb ultraviolet light and some green light bands that are difficult for cells to effectively use, and convert them into a wavelength range that can be absorbed by cells (such as red light or near-infrared light). In practical applications, it can broaden the spectral response range of components to sunlight and improve the utilization rate of light energy. The light absorption efficiency within a specific wavelength range can be increased by 5% - 15%, thereby significantly improving the photoelectric conversion efficiency of the component.

[0041] In the field of packaging materials, the main function of traditional adhesive films is to bond cells and protect the internal structure of components, but the use of the spectrum is not sufficient. Sunlight contains rich spectral components, and conventional adhesive films cannot effectively convert the spectral parts that are difficult for cells to absorb into usable electrical energy, which limits the further improvement of the photoelectric conversion efficiency of the component. The present invention uses fluorescent substances or quantum dot materials as light transfer films, and prepares the light transfer films inside photovoltaic cells. In addition to being able to transmit sunlight normally during the day, this light transfer film will also absorb some excess light and store it; at night or when there is insufficient light, the afterglow of fluorescence can enable the photovoltaic cell to continue to generate electricity, thereby improving the photoelectric conversion efficiency of the component.

[0042] In addition, the back glass 5 can be treated with a black glaze grid, for example, using a black ceramic glaze for coating, the glaze contains black metal oxide components such as iron, cobalt, and nickel, the mass of the glaze accounts for between 10% and 30%, and a uniform black appearance is achieved through a multi-layer coating process (3 to 5 layers).

[0043] Step 4: placing the lamination assembly 7 into a laminator for lamination. The process includes: The lamination temperature is controlled at 140-160℃, the pressure is controlled at 1-2MPa, and the time is 10-20 min, so that each layer of material is tightly combined. For example, the lamination temperature is controlled at 140℃, 145℃, 150℃, 153℃, 160℃, the pressure is controlled at 1 MPa, 1.5 MPa, 2MPa, and the time is 10 min, 15 min, 18 min, 20 min.

[0044] Step five: the laminate assembly 7 is sealed and fixed with an anti-dust frame 8.

[0045] The upper end surface of the conventional frame is higher than the front glass of the laminate assembly 7, which is prone to dust accumulation. Dust accumulation reduces light, causes hot spots, reduces power generation efficiency, and increases operation and maintenance costs.

[0046] Moreover, from the perspective of the overall structure of photovoltaic modules, the existing frame design focuses more on mechanical strength and protection functions, and lacks an effective solution to the dust accumulation problem. In actual outdoor environments, dust easily accumulates near the frame. Over time, the dust will gradually spread to the glass surface, reducing the light transmittance of the glass, thereby affecting the power generation efficiency of the module; moreover, the traditional frame and the components inside the module have poor synergy in optical and thermal performance, and cannot give full play to the overall performance advantages of the module.

[0047] Therefore, the present invention adopts an anti-dust frame 8, the frame material is an aluminum frame or a steel frame. The aluminum frame or the steel frame adopts a black coating process in surface treatment, which can ensure the uniformity and durability of the black appearance while having good weather resistance, wear resistance and corrosion resistance.

[0048] The structure of the anti-dust frame 8 is to remove the upper frame pressing on the front glass, and only retain the supporting frame 82 supported on the bottom of the laminated assembly 7 and the side frame 81 surrounding the laminated assembly 7, and the upper surface of the side frame 81 is not higher than the upper surface of the front glass. Since the photovoltaic components are installed tilted towards the sun, the side frame 81 will not block the dust and debris falling on the front glass, so that the dust falling on the front glass can be easily blown away by the wind, especially on rainy days, when rainwater washes the front glass and washes away the dust on the front glass, thereby reducing the deposition of dust on the front glass.

[0049] The preparation process of the anti-dust frame 8 is as follows: for the aluminum frame, the surface can be pre-treated (such as degreasing, alkali washing, acid washing, etc.) first, and then the black coating can be treated by anodizing or spraying. During anodizing, the electrolyte composition (such as sulfuric acid, oxalic acid, etc.), current density, oxidation time and other parameters are controlled to form a dense oxide film on the surface of the frame, and black dyes or pigments are adsorbed in the film pores to achieve a black appearance and good weather resistance; the spraying process selects a suitable black paint (such as fluorocarbon paint, etc.), and the paint is evenly sprayed on the surface of the frame through a spray gun, and the spraying thickness, curing temperature and time and other parameters are controlled to ensure the adhesion, wear resistance and corrosion resistance of the coating.

[0050] For steel frames, phosphating treatment can be carried out first, and then black coating treatment can be carried out by electrophoretic coating or powder coating process. Similarly, each process parameter must be strictly controlled to achieve ideal coating performance.

[0051] The anti-dust frame 8 structure effectively reduces the adhesion of dust on the frame by changing the frame design. Compared with traditional frames, it can reduce the amount of dust accumulation by 30% - 50%, ensuring the long-term stable operation of photovoltaic modules and reducing the reduction in power generation efficiency caused by dust accumulation.

[0052] In addition, in the application of all-black modules, traditional front glass either has difficulty in achieving the ideal all-black effect and has insufficient anti-glare performance, or has a significant impact on light transmittance while ensuring the black appearance. For example, some simple black coated glass may cause excessive reflection and absorption of light on the glass surface due to the optical properties of the coating, reducing the amount of light reaching the cells. The all-black photovoltaic module provided by the present invention is not simply a black coating on the glass or frame, but a black busbar, a black low-temperature solder strip 2, a black glaze on the back glass 5, and a black frame. The process provides a full-black photovoltaic module, which increases the light absorption of the cell and improves the photoelectric conversion efficiency of the photovoltaic module.

[0053] The improved preparation method of the present invention can prepare including but not limited to 0BB busbar-free cells, TOPCon tunneling oxide layer passivation contact cells, BC back contact cells and HJT heterojunction cells. The preparation processes of these cells can be flexibly combined and applied according to actual needs.

[0054] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0055] Based on the same inventive concept, the present application also provides a full black photovoltaic module, see Figures 1 to 3As shown, it includes a laminate assembly 7 and an anti-dust frame 8 installed around the laminate assembly 7, the laminate assembly 7 includes a battery string 6, the front of the battery string 6 is provided with a front light transfer film 3 and a front tempered glass 1; the back of the battery string 6 is provided with a back light transfer film 4 and a back glass 5, and the back glass 5 is a glazed grid glass; the battery string 6 is welded with a black busbar and a black low-temperature welding strip 2; the anti-dust frame 8 includes a supporting frame 82 supported on the bottom of the laminate assembly 7 and a side frame 81 surrounded by the laminate assembly 7, and the upper end surface of the side frame 81 is flush with the surface of the front tempered glass 1 of the laminate assembly 7.

[0056] The all-black photovoltaic module provided in this application has the following effects: (1) The use of multiple battery technologies in all-black photovoltaic modules means that the modules can integrate the advantages of different battery technologies, thereby potentially improving the overall photoelectric conversion efficiency and performance. At the same time, the all-black appearance also makes it more unique and beautiful in appearance, making it more competitive in some application scenarios that have requirements for appearance. For example, in some building-integrated photovoltaic projects, it can be better integrated with the appearance of the building.

[0057] (2) The material formula and preparation process of the black low-temperature solder strip 2 realize low-temperature welding. This feature can reduce the thermal damage of the battery cell during the welding process, ensure the integrity and performance of the battery cell, and help maintain the stability of the overall performance of the module; and its good electrical connection effect ensures smooth current transmission. At the same time, it has a full black appearance, which can reduce light reflection loss and optimize the light propagation path, which further improves the utilization efficiency of light energy, allowing more light to be effectively absorbed by the battery cell, and ultimately improves the photovoltaic conversion efficiency and overall power generation performance of the module.

[0058] (3) With its specific material formula and matching application, the light transfer film can absorb the spectrum that is difficult for the solar cell to use and convert it into an absorbable wavelength range, which broadens the spectral response range of the module, allowing the module to utilize a wider range of light energy, thereby improving the light energy utilization rate and photoelectric conversion efficiency; and while maintaining an all-black appearance, it has long-term stability to ensure that it can continue to function during long-term use, ensuring that the module maintains a good power generation capacity throughout its life cycle and reducing efficiency losses caused by factors such as material performance degradation.

[0059] (4) The front tempered glass 1 achieves the anti-glare function of the component through careful material selection, preparation process and structural design of the anti-glare layer and the black glaze on the back, which can avoid visual interference and light loss caused by strong light reflection, improve light transmittance and allow more light to enter the component and be used by the battery cells. The all-black appearance meets the overall aesthetic requirements.

[0060] (5) The anti-dust structure design of the frame effectively reduces the impact of dust deposition on the power generation efficiency of the components.

[0061] (6) The overall assembly and packaging process of the components ensures that the components work together by carefully controlling each step, parameter control, and component combination method. This systematic innovation and optimized combination can maximize the advantages of each component and avoid compatibility issues between components, so that the entire component can achieve efficient photoelectric conversion while having good appearance, stability, and reliability, ensuring that the component can stably and efficiently perform its power generation function throughout the entire process from production to commissioning and long-term operation, thereby improving the overall performance and market competitiveness of the product.

[0062] In summary, the advantages of the present invention include but are not limited to improving photoelectric conversion efficiency, enhancing light energy utilization, reducing light reflection loss, having an all-black beautiful appearance, stable and reliable performance of each component, adaptability to long-term outdoor use, convenient maintenance, and ensuring that the components work together efficiently as a whole, etc. It shows advantages in many aspects such as power generation performance, appearance adaptability, service life, and operation and maintenance convenience.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an all-black photovoltaic module, characterized in that: The method comprises: Placing a battery string (6) connected by a lamination process on a front tempered glass (1) provided with a front light transfer film (3); Connecting the black busbar to the battery string (6) according to design requirements, and low-temperature welding the black busbar to the black low-temperature welding strip (2); Laying a back light transfer film (4) on the battery string (6), and laying a back glass (5) on the back light transfer film (4) to form a laminated assembly (7); The lamination assembly (7) is placed in a laminator for lamination.

2. The method for preparing the all-black photovoltaic module according to claim 1, characterized in that: The lamination process includes: a lamination pressure of 0.1-0.3MPa and a lamination temperature of 120-150°C.

3. The method for preparing the all-black photovoltaic module according to claim 1, characterized in that: In the low-temperature welding of the black busbar and the black low-temperature soldering strip (2), the welding temperature is 140-150° C., the welding time is 2-4 s, and the welding pressure is 0.1-0.2 MPa.

4. The method for preparing the all-black photovoltaic module according to claim 1, characterized in that: The composition of the black low-temperature solder strip (2) comprises a low-melting-point alloy matrix and a black pigment; the low-melting-point alloy matrix is ​​an alloy system composed of bismuth, tin and indium; wherein, in terms of mass percentage, the bismuth content is between 40% and 55%, the tin content is between 30% and 45%, and the indium content is between 5% and 20%; the melting point of the black low-temperature solder strip (2) is between 135° C. and 155° C.

5. The method for preparing the all-black photovoltaic module according to claim 4, characterized in that: The black pigment is selected from nano-scale carbon materials or metal oxide materials, and the mass of the black pigment is 1%-3% of the mass of the low-melting-point alloy matrix.

6. The method for preparing the all-black photovoltaic module according to claim 1, characterized in that: The front light transfer film (3) and the back light transfer film (4) are both composed of a base resin and a light conversion material; the base resin comprises an ethylene-vinyl acetate copolymer or a polyolefin elastomer; and the mass concentration of the light conversion material in the front light transfer film (3) and the back light transfer film (4) is 3% to 10%.

7. The method for preparing a fully black photovoltaic module according to claim 6, characterized in that: In the preparation of the light conversion film, a combination of ultrasonic dispersion and surface modifier-assisted dispersion is used to uniformly disperse the light conversion material in the matrix resin.

8. The method for preparing the all-black photovoltaic module according to claim 1, characterized in that: The process of placing the lamination assembly (7) into a laminator for lamination includes: controlling the lamination temperature at 140-160°C, the pressure at 1-2MPa, and the time at 10-20 minutes.

9. The method for preparing a fully black photovoltaic module according to claim 1, characterized in that: The back glass (5) laid on the back light transfer film (4) is glazed grid glass.

10. An all-black photovoltaic module, prepared by the method for preparing an all-black photovoltaic module according to any one of claims 1 to 9, characterized in that: The invention comprises a laminate assembly (7) and an anti-dust accumulation frame (8) installed around the laminate assembly (7), wherein the laminate assembly (7) comprises a battery string (6), wherein the front of the battery string (6) is provided with a front light transfer film (3) and a front tempered glass (1); the back of the battery string (6) is provided with a back light transfer film (4) and a back glass (5), wherein the back glass (5) is glazed grid glass; the battery string (6) is welded by a black busbar and a black low-temperature welding strip (2); the anti-dust accumulation frame (8) comprises a supporting frame (82) supported at the bottom of the laminate assembly (7) and a side frame (81) arranged around the laminate assembly (7), wherein the upper end surface of the side frame (81) is flush with the surface of the front tempered glass (1) of the laminate assembly (7).

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