Nano-porous carbon coated glass powder, preparation method thereof and solar cell silver paste

Abstract

According to the nano-porous carbon coated glass powder, the preparation method thereof and the solar cell silver paste, the nano-porous carbon coated glass powder is prepared with high dispersion uniformity and ideal yield, in the preparation process, it is guaranteed that the glass powder in a system meets the high micron-scale requirement, and the glass powder can be used for preparing the nano-porous carbon coated glass powder. Meanwhile, the nano-porous carbon is adsorbed on the surface of the glass powder, so that agglomeration of glass powder particles is avoided. The nano-porous carbon coated glass powder prepared by the method disclosed by the invention has better particle size distribution, is easy to prepare and is not easy to agglomerate, so that the nano-porous carbon coated glass powder is easier to penetrate through a narrow-line-width screen printing plate in a silk-screen printing process, and the narrow-line-width printing effect is further improved; meanwhile, in the high-temperature sintering process, the nano-porous carbon can form good ohmic contact on an interface, so that the conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present invention relates to a glass powder, a preparation method and a use thereof, and particularly to a glass powder coated with a carbon material, a preparation method and a use thereof, belonging to the technical field of solar cell material preparation. Background Art

[0002] The front silver paste of a solar cell mainly consists of three parts: silver powder, glass powder and an organic carrier. Among them, although the proportion of the bonding phase glass powder in the raw materials is small, its influence on the adhesion between the electrode and the silicon substrate and the photoelectric conversion efficiency of the battery is very large. In order to greatly improve the photoelectric conversion efficiency and reduce the cost, the solar cell is developing towards the direction of N-type high sheet resistance, shallow junction, fine grid and narrow line width. Coupled with the successful application of laser-assisted sintering, higher performance requirements are put forward for the glass powder used in the front silver paste. The glass powder not only plays a role in high-temperature bonding, but also acts as a flux for silver powder sintering and a medium for silver-silicon ohmic contact. During the manufacturing process of the solar cell, the front silver paste is screen-printed into a front electrode pattern. During the subsequent sintering and film-forming process, the glass powder softens, corrodes and penetrates the antireflection film, and mutually fuses with silver particles to form a dense electrode conductive network. Therefore, the glass powder for the front silver paste must have the properties of a lower softening temperature, the ability to penetrate the antireflection film during high-temperature sintering, and a high degree of vitrification.

[0003] The performance of the glass powder directly affects various aspects such as the electrical performance, tensile strength, battery efficiency of the solar cell and the reliability of the subsequent components. At present, the influence of the characteristics of the glass powder on the electrical performance of the solar cell has become a focus of research on crystalline silicon solar cells. Therefore, the improvement of the front silver paste glass powder is imminent.

[0004] An important direction for the improvement of the glass powder is the particle size problem. The size of the glass powder directly affects the effect of screen narrow line width printing and the electrical performance characteristics of the crystalline silicon solar cell. One of the methods to improve the particle size is to prevent the aggregation of micro-nano particles, that is, a coating agent is added during the glass preparation process. At the same time, in order to change the influence of the glass powder on the electrical performance of the solar cell, adding composite components to the glass powder has become a research focus.

[0005] In recent years, with the development of nanotechnology, due to the very high specific surface area of nanoporous carbon, which is usually in the range of several hundred to several thousand square meters per gram. This high specific surface area endows nanoporous carbon with high adsorption capacity and good electrical conductivity; at the same time, its excellent electrical conductivity enables it to have extensive applications in the fields of energy storage and conversion; nanoporous carbon as a composite component has been increasingly emphasized. It has been found that adding nanoscale porous carbon to glass powder has a relatively significant impact on the electrical performance of crystalline silicon solar cells. However, how to add nanoporous carbon as a composite component to glass powder without causing agglomeration of micro- and nano-scale particles and yet significantly changing the electrical performance of solar cells has become one of the key problems to be solved urgently.

[0006] Cracking the agglomeration phenomenon in the process of glass powder improvement has become the goal of current technological research. In addition to improving the original production process, how to smoothly add nanoscale composite components to change the electrical performance of solar cell wafers. Once this key factor is cracked, the efficiency of crystalline silicon solar cells will be significantly improved. Summary of the Invention

[0007] Aiming at the particle size problem of glass powder used in the field of solar silver paste in the prior art and the problem of agglomeration during the surface treatment of glass powder, the purpose of this application is to provide a preparation method of glass powder coated with nanoporous carbon, glass powder coated with nanoporous carbon and its application in solar cell silver paste. The prepared glass powder has the advantages of preventing agglomeration of micro- and nano-scale particles and improving the electrical performance of solar cells.

[0008] According to the first embodiment provided by the present invention, a preparation method of glass powder coated with nanoporous carbon is provided.

[0009] This application provides a preparation method of glass powder coated with nanoporous carbon, and the technical solution is as follows: This preparation method includes the following steps:

[0010] (1) Dispersion system: Disperse the coating agent and nanoporous carbon in a solvent and stir evenly; then add glass powder and stir evenly to obtain a mixture dispersion liquid;

[0011] (2) Grinding: Grind the mixture dispersion liquid to obtain a suspension system of glass powder coated with nanoporous carbon;

[0012] (3) Separation: Remove the solvent from the suspension system of glass powder coated with nanoporous carbon, dry and crush the solid phase to obtain glass powder coated with nanoporous carbon.

[0013] Furthermore, this application also proposes that this preparation method further includes the step:

[0014] (4) Sieving the glass powder coated with nanoporous carbon obtained in step (3) to obtain refined glass powder coated with nanoporous carbon.

[0015] Preferably, the sieving is specifically: sieving the glass powder coated with nanoporous carbon obtained in step (3) through an electromagnetic vibrating sieve with 400 - 600 meshes.

[0016] In the present invention, the particle size of the nanoporous carbon is less than 2 μm. The pore size of the nanoporous carbon is less than 150 nm.

[0017] In the present invention, the weight ratio of the addition amount of the nanoporous carbon to the glass powder is 0.01 - 0.2:1, preferably 0.015 - 0.15:1, more preferably 0.02 - 0.1:1; for example, 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1.

[0018] In the present invention, the coating agent is selected from polymer acids, ethers, ketones, organic salts or esters with a molecular weight of 10,000 - 100,000.

[0019] Preferably, the coating agent is selected from polymer ethers, ketones, organic salts or esters with a molecular weight of 10,000 - 100,000.

[0020] More preferably, the coating agent is selected from one or more of polyvinylpyrrolidone, butyl acrylate, polybutyl methacrylate, polymethyl methacrylate, thiol polyethylene glycol methacrylate, acrylic resin, microgel, alkylphenol polyoxyethylene ether, triphenylstyryl phenol polyoxyethylene ether with a molecular weight of 10,000 - 100,000.

[0021] Even more preferably, the coating agent is selected from polyvinylpyrrolidone and / or triphenylstyryl phenol polyoxyethylene ether with a molecular weight of 10,000 - 100,000.

[0022] Even further preferably, the coating agent is a mixture of polyvinylpyrrolidone and triphenylstyryl phenol polyoxyethylene ether in a weight ratio of 1:0.05 - 0.3, preferably the coating agent is a mixture of polyvinylpyrrolidone and triphenylstyryl phenol polyoxyethylene ether in a weight ratio of 1:0.1 - 0.2. Among them, the molecular weights of polyvinylpyrrolidone and triphenylstyryl phenol polyoxyethylene ether are 10,000 - 100,000.

[0023] In the present invention, the dosage of the coating agent is 0.05% - 30% of the weight of the glass powder, preferably 0.08% - 20%, more preferably 0.1% - 15%.

[0024] In the present invention, the volume ratio of the solvent to the weight of the glass powder is 0.5 - 10 ml:1 g, preferably 0.6 - 5 ml:1 g, and more preferably 1 - 2 ml:1 g.

[0025] In the present invention, any kind of glass powder can be selected as the glass powder, for example, it can be any one of silicate glass powder, borosilicate glass powder, borate glass powder, phosphate glass powder, chalcogenide glass powder, and halide glass powder.

[0026] In the present invention, the particle size Dx(50) of the glass powder is less than 5 μm, preferably less than 3 μm, and more preferably less than 1 μm.

[0027] For example, the Dx(50) of the glass powder used is 0.625 μm (the specific particle size distribution data of this glass powder: Dx(10) 0.397 μm; Dx(50) 0.625 μm; Dx(90) 2.33 μm; Dx(98) 5.07 μm).

[0028] In the present invention, the solvent is an alcohol solvent, and the preferred solvent is ethanol.

[0029] Furthermore, the present application also proposes that the above-mentioned grinding is carried out using an all-round ball mill.

[0030] In the present invention, the grinding time is 0.5 - 6 h, preferably 1 - 4 h.

[0031] As a preference, the above-mentioned separation (step (3)) is specifically: adding a solvent based on 1 g:0.1 - 10 ml of the weight of the glass powder to the suspension system of the glass powder coated with nano-porous carbon, stirring evenly, then removing the solvent in the mixture by centrifugation or distillation, and carrying out vacuum drying on the solid phase at 30 - 60 °C, crushing or grinding to obtain the glass powder coated with nano-porous carbon.

[0032] According to the second embodiment provided by the present invention, a glass powder coated with nano-porous carbon is proposed, and the glass powder coated with nano-porous carbon is obtained by the preparation method described in the first embodiment.

[0033] According to the third embodiment provided by the present invention, a silver paste for a solar cell is proposed.

[0034] A silver paste for a solar cell, the silver paste for a solar cell includes silver powder, an organic carrier, and the glass powder coated with nano-porous carbon obtained by the preparation method described in the first embodiment.

[0035] As a preference, the dosage of the glass powder coated with nano-porous carbon is 0.5 - 5% of the total weight of the silver paste for a solar cell, preferably 1 - 3%.

[0036] In the process of the development of the technical field, the application of glass powder in solar cells has received increasing attention. However, there are certain limitations in uniformly coating nano-porous carbon on glass powder in the prior art, resulting in poor performance of glass powder in practical applications. To overcome these limitations, this application proposes a new preparation method, which realizes the uniform coating of nano-porous carbon through dispersion system, grinding and separation steps, and significantly improves the performance of glass powder.

[0037] The main technical solutions of this application include: First, the coating agent and nano-porous carbon are dispersed in a solvent and stirred evenly, and then glass powder is added and stirring is continued to obtain a mixture dispersion. Next, the mixture dispersion is ground to obtain a suspension system of nano-porous carbon-coated glass powder. Finally, through the separation step, the solvent in the suspension is removed, dried and crushed to obtain glass powder coated with nano-porous carbon. In the process of solving this technical problem, first, the dispersibility of nano-porous carbon and glass powder in the solvent is considered. By selecting appropriate coating agents and solvents, it is ensured that nano-porous carbon and glass powder can be uniformly dispersed. Secondly, through the grinding step, nano-porous carbon can be uniformly coated on the surface of glass powder to form a stable suspension system. Finally, through the separation step, the solvent in the suspension is removed, and drying and crushing are carried out to finally obtain glass powder coated with nano-porous carbon.

[0038] Specifically, in the dispersion step, the coating agent and nano-porous carbon are first dispersed in a solvent, and after stirring evenly, glass powder is added and stirring is continued to form a uniform mixture dispersion. In the grinding step, the mixture dispersion is ground by a ball mill to make nano-porous carbon uniformly coat on the surface of glass powder to form a stable suspension system. In the separation step, the solvent in the suspension is removed by centrifugation or distillation, and drying and crushing are carried out under vacuum drying conditions to finally obtain glass powder coated with nano-porous carbon.

[0039] Compared with the prior art, this application significantly improves the uniformity and stability of nano-porous carbon-coated glass powder by reasonably selecting coating agents and solvents and optimizing the grinding and separation steps. This improvement not only solves the agglomeration problem of nano-porous carbon in glass powder, but also significantly improves the performance of glass powder in solar cells.

[0040] In a preferred technical solution of the present invention, after preparing the glass powder coated with nano-porous carbon, a sieving step is further included, and the glass powder coated with nano-porous carbon is sieved by an electromagnetic vibrating screen. The function of this step is to remove unqualified particles, ensure the particle size uniformity and purity of the final product, and thus improve the performance of the glass powder. By adding the sieving step, unqualified particles can be effectively removed, ensuring the particle size uniformity and purity of the glass powder, further enhancing its application performance in the silver paste of solar cells, and solving the problem of how to further refine the glass powder coated with nano-porous carbon to improve its purity and performance.

[0041] Furthermore, the sieving step of the present application can be achieved in various ways. For example, the vibration frequency and mesh number of the electromagnetic vibrating screen can be adjusted according to actual needs to achieve the best sieving effect. Other types of sieving equipment can also be used as long as the purpose of removing unqualified particles and ensuring particle size uniformity can be achieved. In addition, other auxiliary means, such as air flow sieving and ultrasonic sieving, can be combined during the sieving process to improve the sieving efficiency and effect.

[0042] The inventor found through experimental research that by controlling the particle size of the nano-porous carbon to be less than 2 μm, the agglomeration phenomenon of micro-nano particles can be effectively avoided. By adjusting the weight ratio of the addition amount of nano-porous carbon to the glass powder, the modification performance of the glass powder can be optimized, thus significantly improving the electrical performance of the solar cell. The specific weight ratio range provides a variety of choices, enabling flexible adjustment of the ratio in different application scenarios to achieve the best effect. Through this solution, the nano-porous carbon can be evenly dispersed in the glass powder, thereby improving the photoelectric conversion efficiency of the solar cell, solving the problem of agglomeration of nano-porous carbon in the glass powder, and optimizing the electrical performance.

[0043] The inventors experimented with various coating agents to treat nano-porous carbon-coated glass powder and glass powder. Polymer acids, ethers, ketones, organic salts, or esters with molecular weights ranging from 10,000 to 100,000 (such as polyvinylpyrrolidone, polybutyl acrylate, polybutyl methacrylate, polymethyl methacrylate, thiol polyethylene glycol methacrylate, acrylic resin, microgel, alkylphenol polyoxyethylene ether, or triphenylstyrene phenol polyoxyethylene ether) were selected as coating agents. After being mixed and dispersed with the nano-porous carbon-coated glass powder, they all had an effect on the coating modification of the glass powder. Further experiments found that, compared with other coating agents, using polyvinylpyrrolidone and / or triphenylstyrene phenol polyoxyethylene ether as coating agents, after adding and dispersing the nano-porous carbon-coated glass powder, had a better modification effect on the glass powder. Polyvinylpyrrolidone is a high molecular compound with good dispersibility and film-forming properties, which can effectively coat the nano-porous carbon and glass powder to prevent the aggregation of micro-nano particles. Triphenylstyrene phenol polyoxyethylene ether is a non-ionic surfactant with excellent emulsifying and dispersing properties. When used together with polyvinylpyrrolidone, it can further improve the effect of the coating agent. The inventors further found through experimental research that the mixing ratio of polyvinylpyrrolidone and triphenylstyrene phenol polyoxyethylene ether is 1:0.05 - 0.3, preferably 1:0.1 - 0.2. This ratio can maximize the performance and electrical properties of the glass powder while ensuring the coating effect.

[0044] In the present invention, the dosage of the coating agent is achieved in various ways. For example, the dosage of the coating agent can be controlled by precise weighing and stepwise addition to avoid excess or deficiency. The volume dosage of the solvent can be accurately measured by using a precision graduated cylinder or syringe, and then mixed with the glass powder. To ensure uniform dispersion, technical means such as ultrasonic treatment or high-speed stirring can be adopted.

[0045] The technical solution provided by the present invention can be applied to all glass powders used in the front silver paste of solar energy. By coating and modifying the glass powder with the technical solution provided by the present invention, the aggregation problem of the glass powder can be effectively avoided and the overall performance of the glass powder can be improved.

[0046] The solvent plays a role in dispersion. In the present invention, an alcohol solvent is selected, preferably ethanol, which has good volatility and solubility and can effectively disperse the nano-porous carbon to prevent its aggregation in the glass powder. This property is important for maintaining the uniform distribution of the glass powder and improving the overall performance of the solar cell.

[0047] During the grinding process of the present invention, the use of an all-round ball mill can provide grinding forces in multiple directions, enabling the nano-porous carbon and glass powder to come into full contact and be evenly dispersed within a short period of time. The selection of the grinding time is adjusted according to specific requirements, usually between 0.5 and 6 hours, preferably 1 to 4 hours, to achieve the best grinding effect. In the separation step, the addition ratio of the solvent is 1g:0.1 - 10ml of the weight of the glass powder. After stirring evenly, the solvent is removed by centrifugation or distillation (preferably vacuum distillation), which can effectively remove the excess solvent in the suspension and avoid unevenness during subsequent drying and grinding processes. The vacuum drying process can be carried out under low-temperature conditions to ensure the stability of the material. Finally, the final nano-porous carbon-coated glass powder is obtained by crushing or grinding.

[0048] In the present invention, by adding the nano-porous carbon-coated glass powder prepared by adopting the technical solution of the present invention to the silver paste of a solar cell, the electrical performance of the solar cell can be effectively improved. The functions of the nano-porous carbon-coated glass powder in the silver paste include enhancing the adhesion between the electrode and the substrate, improving the photoelectric conversion efficiency, promoting the sintering of silver powder, and forming a dense conductive network.

[0049] In the present invention, the glass powder can be purchased as commercially available glass powder for the front silver paste of a solar cell, or it can be prepared by oneself. The technical solution for self-preparation is as follows: The weighed oxide raw materials (for example, for silicate glass: the weight ratio of silica powder: limestone: soda ash: fluorspar is 55:25:15:5; for the preparation raw materials of borosilicate glass powder: ω(SiO2) = 70% - 80%, ω(B2O3) = 6% - 15%, ω(Na2O) = 4% - 10%, ω(Al2O3) = 0 - 5%, ω(BaO) = 0 - 2%, ω(CaO) = 0 - 2%;

[0050] for borate glass: the weight ratio of borax: silica powder: soda ash: sodium carbonate is 70:15:10:5; for phosphate glass: the weight ratio of phosphorus pentoxide: aluminum oxide is 55 - 65:4 - 10, and other components optionally include magnesium oxide, zinc oxide, lithium oxide, sodium oxide, potassium oxide; for halide glass: the weight ratio of sodium fluoride: aluminum fluoride: magnesium fluoride is 70:20:10) are fully ground and mixed, then put into a high-temperature furnace for firing, and then poured out and quenched, and finally dried and passed through a 200-mesh sieve to obtain the glass powder. Among them, the firing temperature is 1000°C for 3 hours of heat preservation.

[0051] Compared with the prior art, the technical solution provided by the present invention has the following beneficial technical effects:

[0052] The present application provides a preparation method of glass powder coated with nanoporous carbon, the glass powder coated with nanoporous carbon, and its application in silver paste for solar cells. By dispersing a coating agent and nanoporous carbon in a solvent, adding glass powder, and then grinding and separating, the glass powder coated with nanoporous carbon is obtained, effectively solving the problem of aggregation of micro-nano particles. At the same time, the addition of nanoporous carbon improves the electrical performance of solar cells, having the advantages of preventing the aggregation of micro-nano particles and improving the electrical performance of solar cells. Description of the Drawings

[0053] Figure 1 It is the particle size distribution diagram of the borosilicate glass powder used in the embodiment of the present application;

[0054] Figure 2 It is the particle size distribution diagram of the silicate glass powder used in the embodiment of the present application;

[0055] Figure 3 It is the TG curve of the borosilicate glass powder used in the embodiment of the present application;

[0056] Figure 4 It is the TG curve of the coated glass powder obtained in Example 13 of the present application;

[0057] Figure 5 It is the TG curve of the coated glass powder obtained in Example 1 of the present application;

[0058] Figure 6 It is the TG curve of the coated glass powder obtained in Comparative Example 1 of the present application;

[0059] Figure 7 It is the DSC curve of the borosilicate glass powder used in the embodiment of the present application;

[0060] Figure 8 It is the DSC curve of the coated glass powder obtained in Example 13 of the present application;

[0061] Figure 9 It is the DSC curve of the coated glass powder obtained in Example 1 of the present application;

[0062] Figure 10 It is the DSC curve of the coated glass powder obtained in Example 16 of the present application;

[0063] Figure 11 It is the SEM image of the coated glass powder obtained in Example 13 of the present application;

[0064] Figure 12 It is the SEM image of the coated glass powder obtained in Example 1 of the present application;

[0065] Figure 13 It is the SEM image of the coated glass powder obtained in Example 16 of the present application;

[0066] Figure 14 This is the SEM image of the glass powder obtained after coating in Example 15 of the present application;

[0067] Figure 15 This is the SEM image of the glass powder obtained after coating in Comparative Example 1 of the present application. Detailed implementation manners

[0068] The technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0069] Preparation examples

[0070] A preparation method of glass powder coated with nanoporous carbon, characterized in that the preparation method comprises the following steps:

[0071] (1) Dispersion system: Disperse the coating agent and nanoporous carbon in a solvent and stir evenly; then add glass powder and stir evenly to obtain a mixture dispersion;

[0072] (2) Grinding: Grind the mixture dispersion to obtain a suspension system of glass powder coated with nanoporous carbon;

[0073] (3) Separation: Remove the solvent in the suspension system of glass powder coated with nanoporous carbon, dry and crush the solid phase to obtain glass powder coated with nanoporous carbon;

[0074] (4) Sieve the glass powder coated with nanoporous carbon obtained in step (3) to obtain refined glass powder coated with nanoporous carbon.

[0075] Example 1

[0076] Disperse 2.00 g of polyvinylpyrrolidone coating agent and 2.50 g of nanoporous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder and stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain the nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0077] Example 2

[0078] Disperse 2.00 g of polybutyl acrylate coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain the nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0079] Example 3

[0080] Disperse 2.00 g of polybutyl methacrylate coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain the nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0081] Example 4

[0082] Disperse 2.00 g of polymethyl methacrylate coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operations until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0083] Example 5

[0084] Disperse 2.00 g of mercapto polyethylene glycol methacrylate coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operations until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0085] Example 6

[0086] Disperse 2.00 g of alkylphenol polyoxyethylene ether coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operations until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0087] Example 7

[0088] Disperse 2.00 g of triphenylstyryl phenol polyoxyethylene ether coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain the nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0089] Example 8

[0090] Disperse 2.00 g of polyvinylpyrrolidone coating agent and 0.5 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain the nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0091] Example 9

[0092] Disperse 2.00 g of polyvinylpyrrolidone coating agent and 1 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain the nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0093] Example 10

[0094] Disperse 2.00 g of polyvinylpyrrolidone coating agent and 5 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0095] Example 11

[0096] Disperse 2.00 g of polyvinylpyrrolidone coating agent and 10 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0097] Example 12

[0098] Disperse 1.82 g of polyvinylpyrrolidone and 0.18 g of triphenylstyryl phenol polyoxyethylene ether coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operation until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain the refined nano-porous carbon-coated glass powder.

[0099] Example 13

[0100] Disperse 1.75 g of polyvinylpyrrolidone and 0.25 g of triphenylstyryl phenol polyoxyethylene ether coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operations until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain refined nano-porous carbon-coated glass powder.

[0101] Example 14

[0102] Disperse 1.67 g of polyvinylpyrrolidone, 0.33 g of triphenylstyryl phenol polyoxyethylene ether coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operations until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain refined nano-porous carbon-coated glass powder.

[0103] Example 15

[0104] Disperse 1.43 g of polyvinylpyrrolidone, 0.57 g of triphenylstyryl phenol polyoxyethylene ether coating agent and 2.50 g of nano-porous carbon in 60 ml of ethanol solvent, then add 50.00 g of borosilicate glass powder, stir evenly to obtain a mixture dispersion; add agate balls to the mixture dispersion 150 g 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours, sieve out the agate balls, and obtain a nano-porous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the supernatant, and repeat the above operations until there are no solid particles in the supernatant and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating sieve to obtain refined nano-porous carbon-coated glass powder.

[0105] Example 16

[0106] Disperse 1.75 g of polyvinylpyrrolidone, 0.25 g of alkylphenol polyoxyethylene ether coating agent, and 2.50 g of nanoporous carbon in 60 ml of ethanol solvent. Then add 50.00 g of borosilicate glass powder and stir evenly to obtain a mixture dispersion; add agate balls 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours. Sieve out the agate balls to obtain a nanoporous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the upper clear liquid, and repeat the above operation until there are no solid particles in the upper liquid and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating screen to obtain refined nanoporous carbon-coated glass powder.

[0107] Example 17

[0108] Disperse 1.75 g of polybutyl methacrylate, 0.25 g of triphenylstyryl phenol polyoxyethylene ether coating agent, and 2.50 g of nanoporous carbon in 60 ml of ethanol solvent. Then add 50.00 g of borosilicate glass powder and stir evenly to obtain a mixture dispersion; add agate balls 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours. Sieve out the agate balls to obtain a nanoporous carbon-coated glass powder suspension system; then add 100 ml of absolute ethanol to the above system, stir evenly, centrifuge to remove the upper clear liquid, and repeat the above operation until there are no solid particles in the upper liquid and it is basically clear; vacuum dry and crush the lower solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating screen to obtain refined nanoporous carbon-coated glass powder.

[0109] Example 18

[0110] Disperse 2.00 g of polyvinylpyrrolidone coating agent and 2.50 g of nanoporous carbon in 60 ml of ethanol solvent. Then add 50.00 g of borosilicate glass powder and stir evenly to obtain a mixture dispersion; add agate balls 150 g, 45 g, stir evenly, put into an all-round ball mill and ball mill for 2 hours. Sieve out the agate balls to obtain a nanoporous carbon-coated glass powder suspension system; remove the solvent in the suspension system by vacuum distillation; vacuum dry and crush the solid product at 40 °C, and pass through a 500-mesh electromagnetic vibrating screen to obtain refined nanoporous carbon-coated glass powder.

[0111] Example 19

[0112] Example 1 was repeated except that silicate glass powder was used instead of borosilicate glass powder.

[0113] Embodiment 20

[0114] Example 1 was repeated except that borate glass powder was used instead of borosilicate glass powder.

[0115] Embodiment 21

[0116] Example 1 was repeated except that phosphate glass powder was used instead of borosilicate glass powder.

[0117] Comparative Example 1

[0118] 2.50 g of nanoporous carbon was dispersed in 60 ml of ethanol solvent, and then 50.00 g of borosilicate glass powder was added and stirred evenly to obtain a mixture dispersion; agate balls were added to the mixture dispersion. 150g, 45 grams, stir evenly, put it into an omnidirectional ball mill and ball mill for 2 hours, sieve out the agate balls to obtain a nanoporous carbon-coated glass powder suspension system; then add 100 ml of anhydrous ethanol to the above system, stir evenly, centrifuge to remove the upper clear liquid, repeat the above operation until there are no solid particles in the upper liquid and it is basically clear; vacuum dry and crush the lower solid product at 40°C, and pass it through a 500-mesh electromagnetic vibration sieve to obtain refined nanoporous carbon-coated glass powder.

[0119] The nanoporous carbon-coated glass powder obtained in Examples 1-18 and Comparative Example 1 was subjected to particle size testing according to the industry standard JC / T 650-2023. The experimental results are as follows:

[0120]

[0121] Application Examples

[0122] The nanoporous carbon-coated glass powders obtained in Examples 1-18 and Comparative Example 1 were respectively used as raw materials to prepare solar silver pastes.

[0123] Preparation of solar cell silver paste: 2.0g of coated glass powder, 9.0g of organic vehicle, 88.0g of positive silver powder, 1.0g of oleic acid, and 0.4g of methyl silicone oil prepared in the above embodiments are weighed by mass and added to the reactor; then stirred for 30min using a disperser, mixed evenly, and then ground for 1.5h using a three-roll grinder (to a fineness of less than 6μm) to obtain solar cell silver paste. The organic vehicle is composed of 3% ethyl cellulose, 2% polyamide wax thixotropic agent, 4% dispersant TDO and 91% mixed solvent (alcohol ester twelve: butyl carbitol = 2:1).

[0124] Comparative Example 1 Paste: Borosilicate glass powder purchased on the market (i.e., the raw material in this application, provided by Jinggu Materials Technology Co., Ltd.) was selected. Similarly, 88 g of silver powder for positive silver, 2.0 g of glass powder, 9.0 g of organic carrier, 1.0 g of oleic acid, and 0.4 g of methyl silicone oil were weighed by mass parts. After mixing evenly with a disperser, it was ground with a three-roll mill to a silver paste with a fineness of less than 6 μm. Among them, the organic carrier: consists of 3% ethyl cellulose, 2% polyamide wax thixotropic agent, 4% dispersant TDO, and 91% mixed solvent (alcohol ester twelve: butyl carbitol = 2:1).

[0125] Using the prepared silver paste sample for solar cells, an electrode film was formed on an N-type silicon wafer with a specification of 182 mm × 182 mm by screen printing through a 500-mesh screen, and then sintered in a Despatch sintering furnace, with the peak actual temperature being 700 - 780 °C. The performance of each cell was tested respectively.

[0126] The electrical performance data of the cells were tested using a Berger tester.

[0127] The electrical performance test data are shown in the following table:

[0128]

[0129] As can be seen from the above table, the efficiency of the cells with the N-type battery conductive silver paste prepared in Example 13 of this application is significantly higher than that of the cells with the N-type battery conductive silver paste prepared in Comparative Example 1, and the efficiency has increased by 2.61% (in the current technology, an increase in conversion efficiency of 0.5% is already a significant improvement).

[0130] The contact resistance of the grid lines after printing the paste was tested using a Taiwan Kailong TLM tester, and the contact resistance test data are as follows:

[0131] Example Contact resistance Rc / Ω Example Contact resistance Rc / Ω Example 1 0.52 Example 12 0.49 Example 2 0.72 Example 13 0.47 Example 3 0.67 Example 14 0.49 Example 4 0.73 Example 15 0.63 Example 5 0.70 Example 16 0.64 Example 6 0.75 Example 17 0.67 Example 7 0.75 Example 18 0.55 Example 8 0.64 Example 19 0.57 Example 9 0.61 Example 20 0.53 Example 10 0.59 Example 21 0.56 Example 11 0.63 Comparative Example 1 0.84

[0132] As can be found from the above table, the contact resistance of the cells with the N-type battery conductive silver paste prepared in Examples 1 - 14 of this application is significantly smaller than that of the cells with the N-type battery conductive silver paste prepared in Comparative Example 1. In particular, the contact resistance of the cells with the N-type battery conductive silver paste prepared in Examples 12 - 14 is significantly lower than that of Comparative Example 1.

[0133] The sources of the substances used in the examples of the present invention are as follows:

[0134] Borosilicate glass powder

[0135]

[0136] Silicate glass powder:

[0137]

[0138] Borosilicate glass powder:

[0139]

[0140] Borate glass powder:

[0141]

[0142] Phosphate glass powder:

[0143]

[0144] Nanoporous carbon:

[0145] Manufacturer State Particle size Specific surface area m2 / g Pore size Jiangsu Xianfeng Nano Materials Technology Co., Ltd. Black powder 0.2um - 1.5um >200m2 / g Pore size: ~150nm

[0146] Polyvinylpyrrolidone (CAS: 9003-39-8): Purchased from Gongbik New Materials Technology Co., Ltd., PVP-K25, number average molecular weight 32000, resin content (wt%) > 95, viscosity (mps.s-25°C / 5% ap) 1.7 - 2.1, pH 3.0 - 7.0, K value 22.4 - 27.0, purity 99.3%.

[0147] Triphenylstyryl phenol polyoxyethylene ether (CAS: 99734-09-5): Provided by Hai'an Petrochemical Co., Jiangsu Province, number average molecular weight 59000; cloud point (1% aqueous solution) 90 - 100°C, HLB value 12 - 16, purity 98.6% (model: concentrated emulsion 603).

[0148] Butyl acrylate (CAS: 9003-49-0): Provided by Huayi Chemical Co., Ltd., Suzhou Industrial Park, white emulsion, solid content 45%, viscosity 500 - 1000 cps, particle size 100 - 200 nm, glass transition temperature -50°C, purity 99.5%.

[0149] Butyl polymethacrylate (CAS: 97-88-1): Provided by Shanghai Dongyue High Polymer Materials Co., Ltd., transparent liquid, molecular weight 25000, viscosity 200 - 400 cps, glass transition temperature -10°C, purity 99.0%.

[0150] Polymethyl methacrylate (CAS: 9011-14-7): Provided by Beijing Research Institute of Chemical Industry, transparent particles, molecular weight 12000, density 1.19 g / cm 3 , melting point 160 - 180°C, purity 99.5%.

[0151] Mercapto polyethylene glycol methacrylate (SH-PEG-MA): provided by Xi'an Qiyue Biological, light yellow liquid, molecular weight 13000, viscosity 100-200 cps, pH 5.0-7.0, purity 98.5%.

[0152] Alkylphenol polyoxyethylene ether (CAS: 9036-19-5): purchased from Taizhou Jiayin Chemical Co., Ltd. (NP-10), cloud point (1% aqueous solution) 68-78°C, hydroxyl 87±5mgKNH / g, moisture less than or equal to 1.0%, pH (1% aqueous solution) 5.0-7.0, HLB value 13.3-14, purity 98.8%.

[0153] The grinding process parameters adopted in the present invention are: a planetary ball mill of a certain company is adopted, the grinding medium is agate balls, and the rotation speed of the ball mill is 300 rpm.

[0154] The electromagnetic vibrating screen used in the present invention is an electromagnetic vibrating screen produced by a certain company, with a power of 0.75KW and a vibration frequency of 1500Rpm.

[0155] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing nanoporous carbon-coated glass powder, characterized in that: The preparation method comprises the following steps: (1) Dispersion system: The coating agent and nanoporous carbon are dispersed in a solvent and stirred evenly; then glass powder is added and stirred evenly to obtain a mixture dispersion; (2) grinding: grinding the mixture dispersion to obtain a suspension system of nanoporous carbon-coated glass powder; (3) Separation: removing the solvent in the suspension system of the nanoporous carbon-coated glass powder, drying and crushing the solid phase, and obtaining the nanoporous carbon-coated glass powder.

2. The preparation method according to claim 1, characterized in that: The preparation method also includes the steps of: (4) sieving the nanoporous carbon-coated glass powder obtained in step (3) to obtain refined nanoporous carbon-coated glass powder; Preferably, the screening is specifically: passing the nanoporous carbon-coated glass powder obtained in step (3) through an electromagnetic vibration screen of 400-600 mesh.

3. The preparation method according to claim 1 or 2, characterized in that: The particle size of the nanoporous carbon is less than 2 μm; the pore size of the nanoporous carbon is less than 150 nm; and / or The weight ratio of the added amount of nanoporous carbon to the glass powder is 0.01-0.2:1, preferably 0.015-0.15:1, more preferably 0.02-0.1:1; for example, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:

1.

4. The preparation method according to any one of claims 1 to 3, characterized in that The coating agent is selected from polymer acids, ethers, ketones, organic salts or esters with a molecular weight of 10,000 to 100,000; preferably, the coating agent is selected from polymer ethers, ketones, organic salts or esters with a molecular weight of 10,000 to 100,000; further preferably, the coating agent is selected from one or more of polyvinyl pyrrolidone, polybutyl acrylate, polybutyl methacrylate, polymethyl methacrylate, mercapto polyethylene glycol methacrylate, acrylic resin, microgel, alkylphenol polyoxyethylene ether, and tristyrylphenol polyoxyethylene ether with a molecular weight of 10,000 to 100,000.

5. The preparation method according to claim 4, characterized in that: The coating agent is selected from polyvinyl pyrrolidone and / or tristyrylphenol polyoxyethylene ether with a molecular weight of 10,000 to 100,000; Preferably, the coating agent is a mixture of polyvinyl pyrrolidone and tristyrylphenol polyoxyethylene ether in a weight ratio of 1:0.05-0.3, and preferably the coating agent is a mixture of polyvinyl pyrrolidone and tristyrylphenol polyoxyethylene ether in a weight ratio of 1:0.1-0.

2.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The amount of the coating agent is 0.05%-30% by weight of the glass powder, preferably 0.08%-20%, more preferably 0.1%-15%; and / or The volume ratio of the solvent to the weight ratio of the glass powder is 0.5-10 ml:1 g, preferably 0.6-5 ml:1 g, and more preferably 1-2 ml:1 g.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The glass powder is any one of silicate glass powder, borosilicate glass powder, borate glass powder, phosphate glass powder, chalcogenide glass powder and halide glass powder; The particle size Dx(50) of the glass powder is less than 5 μm, preferably less than 3 μm, more preferably less than 1 μm; and / or The solvent is an alcohol solvent, preferably ethanol.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The grinding in step (2) is performed using an omnidirectional ball mill; the grinding time is 0.5-6h, preferably 1-4h; and / or The step (3) is specifically as follows: adding a solvent in an amount of 0.1-10 ml based on the weight of the glass powder to the suspension system of the nanoporous carbon-coated glass powder, stirring evenly, and then removing the solvent from the mixture by centrifugation or distillation, vacuum drying the solid phase at 30-60° C., crushing or grinding, to obtain the nanoporous carbon-coated glass powder.

9. A nanoporous carbon-coated glass powder, characterized in that: The nanoporous carbon-coated glass powder is prepared by the preparation method described in any one of claims 1 to 8.

10. A solar cell silver paste, characterized in that: The solar cell silver paste comprises silver powder, an organic carrier, and a nanoporous carbon-coated glass powder prepared by the preparation method according to any one of claims 1 to 8; Preferably, the amount of the nanoporous carbon-coated glass powder is 0.5-5% of the total weight of the solar cell silver paste.

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