Multifunctional printing ink and preparation method thereof, and multifunctional coating and preparation method thereof

Abstract

The invention provides multifunctional printing ink and a preparation method thereof, and a multifunctional coating and a preparation method thereof, and relates to the technical field of solar cell manufacturing, and the preparation method of the multifunctional printing ink comprises the following steps: preparing a mixed solvent from trimethylolpropane triacrylate and a high-molecular polymer dispersant; adding nano zirconium oxide and nano aluminum oxide into the mixed solvent, and carrying out ball milling to obtain stable concentrated slurry; carrying out shear mixing on the concentrated slurry, urethane acrylate and a polymerizable UV absorbent at a speed greater than a threshold value to obtain a mixture; and adding a dual-photoinitiator and a rheological additive into the mixture to obtain the multifunctional printing ink. The coating has the characteristics of PID resistance, UV resistance, high refractive index, shear thinning property, UV curing balance and long-term stability; and the anti-PID and anti-UV characteristics and the output power of the solar cell module can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell manufacturing technology, and in particular to a multifunctional printing ink and its preparation method, and a multifunctional coating and its preparation method. Background Technology

[0002] A solar cell module consists of pre-arranged solar cells laminated with an encapsulating film between glass and a backsheet, and encapsulated by a frame. Under long-term high system voltage, a high potential difference is generated between the cells and the module materials such as glass, encapsulating film, backsheet, and frame. This causes charges (usually sodium ions) to migrate from the glass surface through the encapsulating film into the cell, leading to potential-induced degradation (PID). Currently, high-cost POE (Polyethylene ether) films are mainly used to replace traditional EVA films, utilizing their high volume resistivity to block leakage current and ion migration.

[0003] Meanwhile, long-term exposure to ultraviolet (UV) radiation can cause traditional encapsulation films to yellow and age, reducing light transmittance and damaging their insulation properties, ultimately leading to power degradation and failure of the modules. Currently, the main solutions are to add UV absorbers (UVA) and light stabilizers (HALS) to EVA films or module backsheets, or to use POE materials with better UV resistance.

[0004] Furthermore, to minimize light loss at the interface of the encapsulating film and improve the utilization rate of incident light, the encapsulating film needs to have certain optical enhancement properties. Typically, a silicon nitride (SiNx) antireflective film with a refractive index of approximately 1.9-2.1 is prepared on the front side of the solar cell to match the refractive index of the solar cell (n approximately 3.5) and the encapsulating film (n approximately 1.48). Physical textured structures can also be formed on the surface of the solar cell through etching. For example, alkaline etching can form a micro-nano pyramid texture on the surface of monocrystalline silicon cells, while acid etching can form a nanoscale pitted texture on the surface of polycrystalline silicon cells. These physical textured structures reduce reflectivity by increasing the number of reflections of light on the cell surface, thus achieving light trapping.

[0005] In reality, the aforementioned problems of PID effect, UV irradiation, and optical enhancement occur simultaneously in solar cell modules, rather than occurring in isolation. Current solutions to these issues involve identifying functional encapsulant materials that address individual problems and then physically stacking these materials (POE film, EVA containing UV agents, anti-reflective films, etc.). However, the lamination process windows for different encapsulant materials vary, increasing the difficulty of production control. Furthermore, the interfaces between multiple encapsulant materials can become potential failure points during long-term service (such as delamination or cracking). A problem in any one layer can affect the performance and lifespan of the entire solar module. Moreover, achieving high reliability in resisting PID and UV radiation necessitates the use of expensive POE films, increasing costs, and the reliance on imported high-end POE particles poses supply chain risks.

[0006] In view of this, there is an urgent need for a method that can integrate PID resistance, UV resistance and optical enhancement into a single film layer to simplify the manufacturing process and improve the performance and lifespan of battery modules. Summary of the Invention

[0007] The present invention aims to provide a multifunctional printing ink and its preparation method, and a multifunctional coating and its preparation method, in order to at least partially solve at least one of the above-mentioned technical problems.

[0008] To address the aforementioned technical problems, in a first aspect, the present invention provides a method for preparing a multifunctional coating, the method comprising: A mixed solvent was prepared using trimethylolpropane triacrylate and a polymeric dispersant; Nano-zirconia and nano-alumina were added to the mixed solvent and ball-milled to obtain a stable concentrated slurry; The concentrated slurry was shear-mixed with polyurethane acrylate and a polymerizable UV absorber at a rate greater than a threshold to obtain a mixture. Adding a photoinitiator and a rheology modifier to the mixture yields a multifunctional printing ink.

[0009] According to a preferred embodiment of the present invention, the method further includes: weighing the raw materials according to the following mass proportions: Nano-zirconia: 30-35 parts; Nano-alumina: 2-8 parts; Trimethylolpropane triacrylate: 30-40 parts; Polymer dispersant: 2-6 parts; Polyurethane acrylate: 20-30 parts; Polymerizable UV absorber: 1-5 parts; Two photoinitiators: 1-5 parts.

[0010] According to a preferred embodiment of the present invention, the dual photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone in a mass ratio of 2:1.

[0011] To address the aforementioned technical problems, a second aspect of this invention provides a multifunctional printing ink comprising: nano-zirconia, nano-alumina, trimethylolpropane triacrylate, a polymeric dispersant, polyurethane acrylate, a polymerizable UV absorber, a photoinitiator, and a rheology modifier.

[0012] To address the aforementioned technical problems, a third aspect of the present invention provides a method for preparing a multifunctional coating, the method comprising: Ink preparation: Multifunctional printing ink is prepared using any of the above-described methods for preparing multifunctional printing ink; Printing substrate layer: A planar substrate layer is printed on the substrate surface using the aforementioned multifunctional printing ink; Pre-curing: The substrate layer is pre-cured to form a cured substrate layer with a surface gel layer encapsulating an internal liquid or semi-liquid layer; Printed structural layer: A three-dimensional structural layer is printed on the surface of the cured substrate using the aforementioned multifunctional printing ink; Main curing: The curing base layer and structural layer are cured to form a multifunctional coating without physical interfaces.

[0013] According to a preferred embodiment of the present invention, the substrate layer is pre-cured by irradiation with an energy of 50-500 mj / cm2; and / or, the substrate layer and the structural layer are cured by irradiation with an energy of 2000-3000 mj / cm2. The time interval between the pre-curing and the printed structural layer is less than or equal to 2 seconds.

[0014] According to a preferred embodiment of the present invention, the structural layer is a hemispherical microlens array, a biomimetic moth eye array, or a random three-dimensional pattern.

[0015] To solve the above-mentioned technical problems, the fourth aspect of the present invention provides a multifunctional coating, which is prepared by any of the multifunctional coating preparation methods described above.

[0016] To address the aforementioned technical problems, a fifth aspect of the present invention provides a battery assembly comprising a solar cell and glass, wherein the solar cell and glass are provided with a multifunctional coating as described in any one of the above-mentioned claims.

[0017] According to a preferred embodiment of the present invention, an adhesive film layer is provided between the glass and the multifunctional coating, and a refractive index substrate layer is provided between the multifunctional coating and the solar cell.

[0018] According to a preferred embodiment of the present invention, the thickness of the glass is 3~3.5mm, the thickness of the adhesive film layer is 0.44~0.48mm, the thickness of the multifunctional coating is 4~5µm, the thickness of the refractive index substrate layer is 2~15µm, and the thickness of the solar cell is 180~210µm.

[0019] To address the aforementioned technical problems, a sixth aspect of the present invention provides a method for manufacturing a battery module, comprising: Manufacturing solar cells; Using a solar cell as a substrate, a multifunctional coating is prepared on the light-facing surface of one or more solar cells using any of the multifunctional layer preparation methods described above.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention uses trimethylolpropane triacrylate and a polymeric dispersant to prepare a mixed solvent. The polymeric dispersant can simultaneously anchor on the surfaces of two different metal oxides, nano-zirconia and nano-alumina, to form a complete steric hindrance layer, thereby obtaining a long-term stable concentrated slurry. Zirconia and alumina are high-refractive-index nano-metal oxides, and their nano-sized particles can reduce light scattering at the interface and increase the refractive index. (2) In this invention, concentrated slurry is shear-mixed with polymerizable UV absorbers and polyurethane acrylate (PUA) at a rate exceeding a threshold to ensure that the multifunctional printing ink possesses shear-thinning properties, thereby ensuring smooth subsequent printing and accurate structural forming. Simultaneously, the polymerizable UV absorber bonded to the PUA effectively protects the PUA molecular chains from breakage, enabling the PUA to resist external physical wear and impact while simultaneously allowing the polymerizable UV absorber to resist chemical degradation by ultraviolet light. Furthermore, the side-chain polyhydroxy structure in the polyurethane acrylate possesses excellent sodium ion trapping capabilities, which improves resistance to PID (Polydioxanone Injection).

[0021] (3) The present invention incorporates a dual photoinitiator to balance the deep curing speed and the surface curing speed during the subsequent printing curing process, so as to avoid shrinkage stress caused by excessively fast surface curing or poor adhesion caused by insufficient deep curing; and improve the balance of UV curing.

[0022] In summary, the multifunctional printing ink prepared by this invention possesses anti-PID, anti-UV, high refractive index, shear-thinning properties, UV curing uniformity, and long-term stability. After printing a substrate layer using this multifunctional printing ink, the substrate layer is pre-cured at low power, causing preliminary cross-linking of the substrate layer surface molecules to form a chemically reactive surface gel layer encapsulating an internal liquid or semi-liquid cured substrate layer. Then, the multifunctional printing ink is used to print a three-dimensional structural layer on the surface of the cured substrate layer. Because the gel on the surface of the cured substrate layer is already shaped, the printed ink droplets will not collapse or over-spread, forming a three-dimensional structural layer on the surface of the cured substrate layer. Finally, the cured substrate layer and structural layer are cured at high power to form a two-layer integrated, non-physical interface multifunctional coating. This effectively combines the anti-PID, anti-UV, and high refractive index properties of the multifunctional printing ink with the light-trapping properties of the structural layer, achieving a quadruple effect of anti-PID, anti-UV, anti-reflection, and light-trapping. It can effectively improve the anti-PID and anti-UV characteristics of solar cell modules, as well as their output power, while also offering advantages such as high precision, stable structure, simple preparation process, short process, and low equipment investment. Attached Figure Description

[0023] Figure 1 This is a schematic flowchart of a method for preparing a multifunctional printing ink according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a method for preparing a multifunctional coating provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a battery assembly provided in an embodiment of the present invention. Detailed Implementation

[0024] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the invention.

[0025] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0026] This invention provides a method for preparing a multifunctional coating, such as... Figure 1 As shown, the method includes: S1. A mixed solvent is prepared using trimethylolpropane triacrylate and a polymeric dispersant; Trimethylolpropane triacrylate (TMPTA) contains three functional groups, which act as "bridges" during the curing reaction, connecting multiple long polymer chains to form a dense three-dimensional cross-linked network. Polymer dispersants can stably suspend polymers in the form of tiny particles in another medium (usually a liquid, such as water or an organic solvent).

[0027] In one possible implementation, a polymeric dispersant capable of simultaneously anchoring to form a complete steric hindrance layer on the surfaces of two different metal oxides, nano-zirconia and nano-alumina (such as Solsperse) can be selected. ® 39000) is mixed with TMPTA to prepare a mixed solvent, thereby obtaining a stable concentrated slurry and improving the long-term stability of the printing ink. Preferred polymeric dispersants, such as the superdispersant Solsperse... ® 39000, combined with precise dosage calculations, ensures the formation of a complete steric hindrance layer on the particle surface, achieving long-term ink stability.

[0028] S2. Add nano-zirconia and nano-alumina to the mixed solvent and ball mill to obtain a stable concentrated slurry; Zirconia and aluminum oxide are high-refractive-index nano-metal oxides; their nanoscale particle size can reduce light scattering at the interface and increase the refractive index. The ball milling time can be controlled between 3 and 5 hours, preferably 4 hours.

[0029] S3. The concentrated slurry is sheared and mixed with polyurethane acrylate and polymerizable UV absorber at a speed greater than a threshold to obtain a mixture; The system comprises polyurethane acrylate (PUA) and a polymerizable UV absorber (UV-AM) to form a UV-curing system. The UV-AM, bonded to the PUA, effectively protects the PUA molecular chains from breakage, enabling PUA to resist external physical wear and impact while simultaneously protecting UV-AM from chemical degradation by ultraviolet light. Furthermore, the polyhydroxyl side chains in PUA possess excellent sodium ion trapping capabilities, enhancing its resistance to PID (Polydioxanone Inhibition).

[0030] In this step, the concentrated slurry prepared in step S1, along with PUA and UV-AM, can be placed in a dispersion vessel and shear-mixed at a speed exceeding a threshold using a high-speed dispersion machine or similar equipment. This ensures that the multifunctional printing ink possesses shear-thinning properties. Consequently, the viscosity of the prepared multifunctional printing ink is significantly reduced at the high shear rate at the printhead, and quickly recovers its viscosity after ejection. This effectively ensures smooth subsequent printing and accurate structural formation. The threshold can be configured according to actual needs (e.g., speed greater than 20 m / s).

[0031] S4. Add a dual photoinitiator and a rheology modifier to the mixture to obtain a multifunctional printing ink.

[0032] The dual photoinitiator can include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173) in a mass ratio of 2:1. This balances the deep curing rate and surface curing rate during subsequent printing and curing processes, avoiding shrinkage stress caused by excessively rapid surface curing or poor adhesion due to insufficient deep curing, thus improving the balance of UV curing. Rheology modifiers can include fumed SiO2, polyamide wax, etc.

[0033] This step yields a multi-functional printing ink with a viscosity of 10-30 cp and a shelf life of more than 6 months. The preferred viscosity is 15 cp. In practice, the viscosity of the multi-functional printing ink can be adjusted by changing the mass fraction of each component, the ball milling time, and the shear rate.

[0034] In one possible implementation, before step S1 of preparation, the raw materials can be weighed in the following proportions by mass: Nano-zirconia: 30-35 parts; Nano-alumina: 2-8 parts; Trimethylolpropane triacrylate: 30-40 parts; Polymer dispersant: 2-6 parts; Polyurethane acrylate: 20-30 parts; Polymerizable UV absorber: 1-5 parts; Two photoinitiators: 1-5 parts.

[0035] In a preferred embodiment, the raw materials are weighed according to the following parts by weight: Nano-zirconia: 32 parts; Nano-alumina: 5 parts; Trimethylolpropane triacrylate: 35 parts; Polymer dispersant: 3 parts; Polyurethane acrylate: 25 parts; Polymerizable UV absorber: 3 parts; Two photoinitiators: 3 parts; The preparation process of this embodiment is as follows: First, synergistic stabilization is carried out by adding 32 parts of nano-zirconia and 5 parts of nano-alumina to a mixed solvent formed by 35 parts of trimethylolpropane triacrylate and 3 parts of polymer dispersant (superdispersant), and forming a stable concentrated slurry by high-energy grinding balls for 4 hours; functional mixing is achieved by adding the concentrated slurry to a dispersion vessel and adding 25 parts of polyurethane acrylate (PUA) and 3 parts of polymerizable UV absorber (UV-AM) for high-speed shear mixing; then the entire system is regulated by adding 3 parts of dual photoinitiator (containing 2 parts of TPO + 1 part of 1173) and rheology modifier to the mixed mixture to form a four-function printing ink with a viscosity of 15cp (50) and a shelf life of more than 6 months.

[0036] based on Figure 1 The multifunctional printing ink preparation method shown in the present invention also provides a multifunctional printing ink prepared by the multifunctional printing ink preparation method described in the above embodiments. The multifunctional printing ink may include: nano-zirconia, nano-alumina, trimethylolpropane triacrylate, polymer dispersant, polyurethane acrylate, polymerizable UV absorber, photoinitiator and rheology modifier.

[0037] In one possible implementation, the mass fractions of each component are: Nano-zirconia: 30-35 parts; Nano-alumina: 2-8 parts; Trimethylolpropane triacrylate: 30-40 parts; Polymer dispersant: 2-6 parts; Polyurethane acrylate: 20-30 parts; Polymerizable UV absorber: 1-5 parts; Two photoinitiators: 1-5 parts.

[0038] In a preferred embodiment, the mass fractions of each component are as follows: Nano-zirconia: 32 parts; Nano-alumina: 5 parts; Trimethylolpropane triacrylate: 35 parts; Polymer dispersant: 3 parts; Polyurethane acrylate: 25 parts; Polymerizable UV absorber: 3 parts; Two photoinitiators: 3 parts.

[0039] based on Figure 1 The multifunctional printing ink preparation method shown in this invention provides a method for preparing a multifunctional coating, such as... Figure 2 As shown, the method includes: S101, Printing the base layer: In this embodiment, the following is adopted: Figure 1 The multifunctional printing ink prepared by the method shown can be used to print a planar substrate layer on the surface of a substrate. The substrate can be a device using the multifunctional coating prepared according to this invention as a component, such as a solar cell (BC, TOPCon, HJT); or it can be equipment specifically used to prepare the multifunctional coating; this invention does not impose any specific limitations.

[0040] In one possible implementation, this step involves conveying the substrate to a first inkjet printing station, where a flat, planar substrate layer with a thickness of 10µm is printed using a piezoelectric printhead (15 pL liquid volume). An example of substrate delivery to the station could be loading a substrate, such as a solar cell, onto a conveyor belt via automated equipment and then transporting it to the appropriate station or processing station (first inkjet printing station, pre-curing station, second inkjet printing station, main curing station, etc.).

[0041] S102, Pre-curing: Pre-curing the base layer to form a cured base layer with a surface gel layer encapsulating the internal liquid or semi-liquid.

[0042] In this embodiment, a low-power UV curing device is used to pre-cur the substrate layer to allow initial cross-linking of the surface molecules, forming a cured substrate layer with a surface gel layer encapsulating the internal liquid or semi-liquid. The surface of this cured substrate layer is a gel layer with a thickness less than a predetermined thickness, and this gel layer encapsulating the internal liquid or semi-liquid gives it chemical reactivity. The predetermined thickness must meet the requirements for chemical reactivity; for example, the predetermined thickness could be 0.1 µm. The low power can be any power value less than a first preset power, which can be set according to actual needs; for example, the first preset power could be 4 W / cm².

[0043] In one possible implementation, after the substrate layer is printed, the substrate is immediately placed in a low-power single-wavelength (395nm) LED-UV pre-curing station to receive 50-500mJ / cm². 2 The substrate is pre-cured for a predetermined time by irradiating it with energy. Specifically, the energy needs to be precisely controlled between 50-500 mJ / cm². 2 Within this range, on the one hand, it can avoid the phenomenon that the gel layer cannot be formed on the surface of the solidified substrate due to insufficient energy, resulting in the solidified substrate still being liquid, which would cause the subsequent printed structural layer to collapse; on the other hand, it can avoid the phenomenon that the gel layer on the surface of the solidified substrate is too thick due to excessive energy, resulting in over-curing, which would reduce the adhesion of the subsequent printed structural layer and make it difficult to form an interface-free structure between the solidified substrate and the structural layer.

[0044] In practice, the power and irradiation time of the LED-UV curing station can be controlled to ensure that the energy is kept between 50-500 mJ / cm². 2 Within a certain range. For example, the substrate layer can be cured at 120 mJ / cm² in a 395 nm LED-UV curing station. 2 Pre-curing is achieved by irradiating the material with energy for 0.8 seconds.

[0045] S103, Printing structural layer: use Figure 1 The multifunctional printing ink prepared by the method shown can print a three-dimensional structure layer on the surface of the cured substrate layer. In this embodiment, the time interval between steps S2 and S3 must be less than or equal to 2 seconds. That is, the time interval from the completion of pre-curing in step S2 to the start of printing the structural layer in step S3 must be less than or equal to 2 seconds. This ensures that the active groups inside the cured substrate layer remain highly active and can form sufficient chemical bonds with the multifunctional printing ink of the structural layer.

[0046] The structural layer has excellent light-trapping effect due to its three-dimensional structure, which can be generated by pre-designing a microstructure model; for example, the structural layer can be a hemispherical microlens array, a biomimetic moth eye array, or a random three-dimensional pattern generated by a computer program or user instructions.

[0047] In one possible implementation, this step involves feeding the substrate into a second inkjet printing station. The inkjet printer then prints a hemispherical microlens array consisting of hemispherical microlenses with a diameter of 20µm and a height of 5µm onto the "pinned" cured substrate layer. Since a cured substrate layer with a surface gel layer encapsulating an internal liquid or semi-liquid layer is formed in step S2, and this surface gel layer is already shaped, the UV ink droplets printed on it in this step will neither collapse nor spread excessively, ensuring the printing effect of the structural layer. Preferably, before printing, the initial printing position of the printing equipment can be aligned with the initial position of the cured substrate layer (e.g., edges, vertices), and the alignment accuracy can be controlled within ±10µm to ensure the structural integrity of the three-dimensional structural layer.

[0048] S104. Main curing: Curing the base layer and structural layer to form a multifunctional coating without physical interfaces.

[0049] This step requires the use of high-power UV curing equipment to cure the substrate layer and structural layer, ensuring complete and uniform cross-linking and curing of this two-layer structure to form a chemically bonded, integrated, multifunctional coating without physical interfaces. The high power can be any power value greater than a second preset power, which can be set according to actual needs; for example, the second preset power could be 8 W / cm².

[0050] In one possible implementation, after printing the 3D structure layer, the substrate is immediately placed in a high-power dual-wavelength (365nm+395nm) LED-UV main curing station, receiving 2000-3000mJ / cm². 2 The substrate and structural layers are cured by irradiation with energy; preferably 2500 mJ / cm. 2 The energy is used to irradiate the base layer and structural layer to cure them.

[0051] In practice, the power and irradiation time of the LED-UV curing station can be controlled to ensure that the energy is kept between 2000-3000 mJ / cm². 2 That's possible. For example, the substrate and structural layers can be cured at 2500 or 2800 mJ / cm² in a 365nm+395nm LED-UV curing station. 2 It was cured by irradiating it with energy for 2 seconds.

[0052] In the actual preparation process, the surface tension of the multifunctional printing ink can be optimized by adjusting the component ratio and ball milling time within the range of the above process parameters. The main curing parameters can be optimized by adjusting the main curing energy, power, and time. Combined with optimizing the pre-curing timing, this ensures that the morphological fidelity of the microstructure of the finally cured multifunctional coating is greater than 95% with that of the pre-designed microstructure model.

[0053] based on Figure 2 The present invention provides the following specific embodiments of a method for preparing a multifunctional coating: Example 1: Using 35 parts TMPTA and 3 parts Solsperse ® A mixed solvent was prepared using a 39000-fold method. 32 parts of nano-zirconia and 5 parts of nano-alumina were added to the mixed solvent and ball-milled to obtain a stable concentrated slurry. The concentrated slurry was then shear-mixed with 25 parts of polyurethane acrylate and 3 parts of polymerizable UV absorber at a speed exceeding a threshold to obtain a mixture. 3 parts of a dual-photoinitiator (2 parts TPO and 1 part 1173) and a rheology modifier were added to the mixture to obtain a multifunctional printing ink. An 8μm planar substrate layer was printed on the substrate surface using this multifunctional printing ink. Pre-curing was performed using a low-power 395nm LED-UV curing station at 120mJ / cm² energy to obtain a cured substrate layer. A 5μm high hemispherical microlens array structure layer was then printed on the cured substrate layer using the same multifunctional printing ink. Finally, a high-power 365nm+395nm LED-UV curing station at 2500mJ / cm² energy was used for main curing to obtain a multifunctional coating.

[0054] Example 2: Same as Example 1, except that: nano-zirconia: 33 parts; nano-alumina: 8 parts; trimethylolpropane triacrylate: 37 parts; Solsperse ® 39000: 2 parts; polyurethane acrylate: 22 parts; polymerizable UV absorber: 4 parts; dual photoinitiator: 2 parts (2 / 3 parts TPO and 1 / 3 parts 1173).

[0055] Example 3: Same as Example 1, except that the substrate used is a BC battery.

[0056] In addition, to verify the performance of the multifunctional coating prepared by the above method, the present invention also provides the following comparative examples: Comparative Example 1: Existing high-end POE film.

[0057] Comparative Example 2: Traditional EVA film.

[0058] Comparative Example 3: Same as Example 1, except that the ball milling time was less than 1 hour, and gelation occurred.

[0059] Comparative Example 4: Same as Example 1, except that the pre-curing energy is 600 mJ / cm². 2 Excessive pre-curing.

[0060] The multifunctional coatings prepared in Examples 1-3 and the coatings prepared in Comparative Examples 1-4 were used as encapsulation materials between solar cells and glass. The performance test results are shown in Table 1.

[0061] As can be seen from Table 1, the multifunctional coating prepared by the present invention is superior to the comparative example in terms of ink stability, adhesion after curing, resistance to PID degradation, and resistance to UV aging. This proves that the multifunctional coating prepared by the present invention can effectively improve the resistance to PID and UV of solar cell modules.

[0062] Based on the above-described method for preparing a multifunctional coating, this embodiment of the invention also provides a multifunctional coating, which is prepared by any of the methods described above.

[0063] For example, the multifunctional coating may include a planar substrate layer and a structural layer without a physical interface, both of which are printed using the multifunctional printing ink described above, and the structural layer has a three-dimensional structure. In this multifunctional coating, the substrate layer is printed using multifunctional printing ink, providing anti-PID, anti-UV, and high refractive index properties; the structural layer has a three-dimensional structure, providing excellent light-trapping effect. Simultaneously, the structural layer is also printed using the same multifunctional printing ink as the substrate layer, and there is no physical interface between the substrate layer and the structural layer. Therefore, the anti-PID, anti-UV, and high refractive index properties of the substrate layer can be effectively combined with the light-trapping properties of the structural layer, achieving a quadruple effect of anti-PID, anti-UV, anti-reflection, and light-trapping.

[0064] The substrate layer has a thickness of 5-10 μm, and the structural layer has a thickness of 3-8 μm. The structural layer can be a hemispherical microlens array, a biomimetic moth-eye array, or a random three-dimensional pattern generated by a computer program or user instructions. Taking a hemispherical microlens array as an example, it can consist of multiple hemispherical microlenses with a diameter of 20 µm and a height of 5 µm. The thickness of the structural layer refers to the vertical length from the lowest point to the highest point within the structural layer. For example, the height of the hemispherical microlenses in the structural layer of a hemispherical microlens array is the thickness of that structural layer.

[0065] The multifunctional printing ink includes: nano-zirconia, nano-alumina, trimethylolpropane triacrylate, polymer dispersant, polyurethane acrylate, polymerizable UV absorber, photoinitiator and rheology modifier.

[0066] Based on the above-described method for preparing a multifunctional coating, this invention provides a battery assembly, such as... Figure 3As shown, it includes: solar cell 21 and glass 22, with the multifunctional coating 23 described above filling the space between the light-facing surface of the solar cell 21 and the glass 22. Multiple solar cells 21 can be connected in series to form a battery string. These battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between individual solar cells can be achieved by welding ribbons, or the connection between battery strings can be achieved by busbars.

[0067] In one possible implementation, such as Figure 3 As shown, the battery assembly may further include an encapsulant layer 24 and a refractive index substrate layer 25. The encapsulant layer 24 can be filled between the multifunctional coating 23 and the glass 22. The encapsulant layer 24 can be a transparent colloid with good light transmission and aging resistance, such as EVA film or POE film. The specific choice can be made according to the actual situation and is not limited here. The refractive index substrate layer 25 can be filled between the multifunctional coating 23 and the light-facing surface of the solar cell 21. The refractive index substrate layer 25 can be a transparent colloid with good light transmission and a refractive index between that of the solar cell 21 (n is approximately 3.5) and the encapsulant layer 24 (n is approximately 1.48). For example, the refractive index substrate layer 25 can be a POE film. The specific choice can be made according to the actual situation and is not limited here. For example, the solar cell 21 may be a silicon cell with a thickness of 180-210µm, the refractive index substrate layer 25 has a thickness of 2-15µm, the multifunctional coating 23 has a thickness of 4-5µm, the encapsulant layer 24 has a thickness of 0.46mm, and the glass 22 may be tempered glass with a thickness of 3.2mm.

[0068] In one possible implementation, the solar cell module may further include a metal frame and a backsheet. The encapsulant layer 24 may further fill the space between the back surface of the solar cell 21, the backsheet, and adjacent cells.

[0069] Based on the above-described method for preparing a multifunctional coating, this invention also provides a method for manufacturing a solar cell module, the method comprising: S101, Manufacturing solar cells; This step can be accomplished using existing processes to manufacture solar cells (such as n-type BC cells, PERC cells, TOPCon cells, and HJT cells), and will not be elaborated further here.

[0070] S102. Using a solar cell as a substrate, a multifunctional coating is fabricated on the light-facing surface of one or more of the solar cells using any of the above-described methods for preparing multifunctional coatings.

[0071] In summary, the multifunctional printing ink and its preparation method, as well as the multifunctional coating and its preparation method provided by this invention, have at least the following beneficial effects compared to the prior art: 1. This invention uses trimethylolpropane triacrylate and a polymeric dispersant to prepare a mixed solvent. The polymeric dispersant can simultaneously anchor on the surfaces of two different metal oxides, nano-zirconia and nano-alumina, to form a complete steric hindrance layer, resulting in a long-term stable concentrated slurry. Zirconia and alumina are high-refractive-index nano-metal oxides, and their nanoscale particle size can reduce light scattering at the interface and increase the refractive index. 2. This invention involves shear mixing concentrated slurry with a polymerizable UV absorber and polyurethane acrylate (PUA) at a rate exceeding a threshold. This ensures the multifunctional printing ink possesses shear-thinning properties, guaranteeing smooth printing and precise structural formation. Simultaneously, the polymerizable UV absorber, bonded to the PUA, effectively protects the PUA molecular chains from breakage, enabling the PUA to resist external physical wear and impact while simultaneously allowing the polymerizable UV absorber to resist chemical degradation by ultraviolet light. Furthermore, the side-chain polyhydroxyl structures in the polyurethane acrylate possess excellent sodium ion trapping capabilities, enhancing resistance to PID (Polydioxanone Acrylates).

[0072] 3. This invention incorporates a dual photoinitiator to balance the deep curing speed and surface curing speed during the subsequent printing and curing process, avoiding shrinkage stress caused by excessively rapid surface curing or poor adhesion due to insufficient deep curing; thus improving the balance of UV curing.

[0073] 4. This invention uses a multifunctional printing ink with anti-PID, anti-UV, and high refractive index properties to print a planar substrate layer and pre-cur it before printing a three-dimensional structure layer on its surface. The two are then cured to form a multifunctional coating with dual-layer integration, no physical interface defects, anti-PID, anti-UV, high refractive index, and light-trapping properties, thereby achieving the effects of anti-PID, anti-UV, light-trapping, and anti-reflection.

[0074] 5. This invention uses inkjet printing and curing technology to achieve the manufacturing of high-precision, structurally stable, and flexible coatings, with advantages such as simple process, convenient operation, and low manufacturing cost; at the same time, it can be seamlessly integrated with existing production lines.

[0075] 6. The multifunctional coating manufactured by this invention is designed for an adhesive film environment, with extremely high structural fidelity and adhesion after TC200, resulting in excellent encapsulation performance.

[0076] It should be clarified that the present invention is not limited to the specific structures and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known structures are omitted here. In the above embodiments, several specific structures are described and shown as examples. However, the lens cleaning device of the present invention is not limited to the specific structures described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the installation positions between structures, after understanding the spirit of the present invention.

[0077] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the structures, modules, and units described above can be referred to the corresponding processes in the foregoing embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A method for preparing a multifunctional printing ink, characterized in that, include: A mixed solvent was prepared using trimethylolpropane triacrylate and a polymeric dispersant; Nano-zirconia and nano-alumina were added to the mixed solvent and ball-milled to obtain a stable concentrated slurry; The concentrated slurry was shear-mixed with polyurethane acrylate and a polymerizable UV absorber at a rate greater than a threshold to obtain a mixture. Adding a photoinitiator and a rheology modifier to the mixture yields a multifunctional printing ink.

2. The method for preparing the multifunctional printing ink according to claim 1, characterized in that, Also includes: Weigh the raw materials according to the following mass proportions: Nano-zirconia: 30-35 parts; Nano-alumina: 2-8 parts; Trimethylolpropane triacrylate: 30-40 parts; Polymer dispersant: 2-6 parts; Polyurethane acrylate: 20-30 parts; Polymerizable UV absorber: 1-5 parts; Two photoinitiators: 1-5 parts.

3. The method for preparing the multifunctional printing ink according to claim 1 or 2, characterized in that, The dual photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone in a mass ratio of 2:

1.

4. A multifunctional printing ink prepared by the method for preparing multifunctional printing ink according to any one of claims 1-3, characterized in that, include: Nano-zirconia, nano-alumina, trimethylolpropane triacrylate, polymer dispersant, polyurethane acrylate, polymerizable UV absorber, photoinitiator and rheology modifier.

5. A method for preparing a multifunctional coating, characterized in that: include: Ink preparation: The multifunctional printing ink is prepared using the preparation method of the multifunctional printing ink according to any one of claims 1-3; Printing substrate layer: A planar substrate layer is printed on the substrate surface using the aforementioned multifunctional printing ink; Pre-curing: The substrate layer is pre-cured to form a cured substrate layer with a surface gel layer encapsulating an internal liquid or semi-liquid layer; Printed structural layer: A three-dimensional structural layer is printed on the surface of the cured substrate using the aforementioned multifunctional printing ink; Main curing: The curing base layer and structural layer are cured to form a multifunctional coating without physical interfaces.

6. The method for preparing a multifunctional coating according to claim 5, characterized in that, Using 50-500mj / cm 2 Pre-curing the substrate by irradiating it with energy; and / or by using 2000-3000 mJ / cm 2 The energy irradiation is used to solidify the substrate and structural layers; The time interval between the pre-curing and the printed structural layer is less than or equal to 2 seconds.

7. The method for preparing a multifunctional coating according to claim 5 or 6, characterized in that, The structural layer is a hemispherical microlens array, a biomimetic moth eye array, or a random three-dimensional pattern.

8. A multifunctional coating, characterized in that, The multifunctional coating is prepared using the method described in any one of claims 5-7.

9. A battery assembly, comprising: Glass and solar cell, characterized in that a multifunctional coating as described in claim 8 is provided between the glass and the solar cell.

10. The battery assembly according to claim 9, characterized in that, An adhesive film layer is provided between the glass and the multifunctional coating, and a refractive index substrate layer is provided between the multifunctional coating and the solar cell.

11. The battery assembly according to claim 10, characterized in that, The thickness of the glass is 3~3.5mm, the thickness of the adhesive film layer is 0.44~0.48mm, the thickness of the multifunctional coating is 4~5µm, the thickness of the refractive index substrate layer is 2~15µm, and the thickness of the solar cell is 180~210µm.

12. A method for manufacturing a battery module, characterized in that, include: Manufacturing solar cells; Using a solar cell as a substrate, a multifunctional coating is prepared on the light-facing surface of one or more solar cells using the multifunctional layer preparation method described in any one of claims 5-7.

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