阅读说明：本技术 光伏组件用镀膜液、其制备方法及光伏组件 (Coating liquid for photovoltaic module, preparation method of coating liquid and photovoltaic module ) 是由 卢王威 刘俊辉 陶武松 郭志球 于 2020-06-30 设计创作，主要内容包括：本发明属于光伏材料技术领域,提供了一种光伏组件用镀膜液、其制备方法及光伏组件。本发明所提供的光伏组件用镀膜液包含醇溶剂及分散于醇溶剂中的二氧化硅纳米颗粒和二氧化钒@二氧化硅纳米颗粒；所述二氧化钒@二氧化硅纳米颗粒为壳层包覆内核的核壳结构,所述内核为二氧化钒,所述壳层为二氧化硅层,所述二氧化硅层的表面具有二氧化硅枝杈晶。采用本发明的镀膜液对光伏组件进行镀膜,可使光伏组件自动调节高低温环境下对近红外光的透过率,具有自主温度调控特性；同时还使光伏组件具有优异的防水性能,有利于延长光伏组件的使用寿命。(The invention belongs to the technical field of photovoltaic materials, and provides a coating liquid for a photovoltaic module, a preparation method of the coating liquid and the photovoltaic module. The coating liquid for the photovoltaic module comprises an alcohol solvent, and silicon dioxide nanoparticles and vanadium dioxide @ silicon dioxide nanoparticles which are dispersed in the alcohol solvent; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer. The photovoltaic module is coated by the coating liquid, so that the photovoltaic module can automatically adjust the transmittance of near infrared light in high and low temperature environments, and has the characteristic of autonomous temperature regulation; meanwhile, the photovoltaic module has excellent waterproof performance, and the service life of the photovoltaic module is prolonged.)

1. The coating liquid for the photovoltaic module is characterized by comprising an alcohol solvent, and silica nanoparticles and vanadium dioxide @ silica nanoparticles which are dispersed in the alcohol solvent;

the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer.

2. The coating solution for photovoltaic modules as claimed in claim 1, wherein the molar ratio of said silica nanoparticles to said vanadium dioxide @ silica nanoparticles is 1: 40-40: 1; preferably 1: 1-40: 1.

3. the coating solution for photovoltaic modules as claimed in claim 1, wherein the silica nanoparticles and the vanadium dioxide @ silica nanoparticles have a particle size of 200 to 300 nm, respectively.

4. The coating solution for photovoltaic modules according to claim 1, wherein said alcohol solvent is at least one selected from methanol, ethanol, propanol and isopropanol.

5. The method for preparing a coating solution for photovoltaic modules according to any one of claims 1 to 4, comprising the steps of:

s1: preparation of vanadium dioxide @ silica nanoparticles:

dissolving vanadium dioxide nanoparticles and a silicon precursor in an alcohol solvent, adding a dispersion system, stirring, placing in a hydrothermal reaction kettle, and reacting at 150-300 ℃ for 12-16 hours to obtain a dispersion system containing vanadium dioxide @ silicon dioxide nanoparticles;

the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer;

s2: preparing a coating liquid for the photovoltaic module:

and mixing the dispersion system containing the vanadium dioxide @ silicon dioxide nano particles with a coating liquid containing the silicon dioxide nano particles, or adding the silicon dioxide nano particles into the dispersion system containing the vanadium dioxide @ silicon dioxide nano particles to obtain the coating liquid for the photovoltaic module.

6. The method of claim 5, wherein the silicon precursor is at least one selected from methyltrimethoxysilane, vinyltrimethoxysilane, and tetraethoxysilane.

7. The method for preparing a coating liquid for a photovoltaic module according to claim 5, wherein the dispersion is one or more selected from the following reagent combinations: oxalic acid and ammonia, citric acid and ammonia, oxalic acid and sodium bicarbonate.

8. A photovoltaic module, comprising a transparent substrate and a coating layer provided on the transparent substrate, wherein the coating layer is formed by coating the photovoltaic module with the coating liquid according to any one of claims 1 to 4.

9. The photovoltaic module of claim 8 wherein the coating comprises silica nanoparticles and vanadium dioxide @ silica nanoparticles;

the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer.

10. The photovoltaic module of claim 9 wherein the silica nanoparticles and the vanadium dioxide @ silica nanoparticles are present in a molar ratio of 1: 40-40: 1; preferably 1: 1-40: 1.

Technical Field

The invention belongs to the technical field of photovoltaic materials, and particularly relates to a coating liquid for a photovoltaic module, a preparation method of the coating liquid and the photovoltaic module.

Background

With the continuous improvement of the efficiency of the solar cell, the photoelectric conversion efficiency of the single-section solar cell is close to the theoretical efficiency, the photoelectric conversion efficiency is difficult to be greatly improved through the research and development of the cell and the improvement of the process, and meanwhile, the design of the photovoltaic module becomes one of the key factors restricting the development of the solar cell. How to reduce the power attenuation of the photovoltaic module in the application is increasingly a problem with high industrial value.

In a photovoltaic module system, on the one hand, due to the radiation of sunlight, energy is absorbed by the photovoltaic module, resulting in an increase in the temperature of the system; on the other hand, along with the operation of the component system, the operation temperature of the component is promoted, and especially when the photovoltaic component operates under the partial shadow condition, the area which is not shielded by the shadow and the shielded area simultaneously operate under the PN junction reverse bias state, at this time, the area which is not shielded can be regarded as an equivalent load, and the electric energy formed by the area which is not shielded in the component system is consumed by the area and is converted into the heat energy to form the hot spot. The high temperature caused by the hot spot phenomenon not only promotes irreversible damage such as aging of the photovoltaic module, but also causes fire disaster even if the local high temperature. Therefore, in addition to avoiding the hot spot phenomenon of the photovoltaic module, how to intelligently and effectively reduce the working temperature of the photovoltaic module is particularly important.

At present, aiming at the problem of heat dissipation of a photovoltaic module, two methods of air cooling and water cooling are mainly adopted at home and abroad. For air cooling, on one hand, the introduction of the fan brings the consumption of electric energy, and on the other hand, the service life of the existing fan product is short, and the fan is easy to be damaged by extreme environment. Compared with air cooling, although the water cooling heat dissipation effect is better and partial heat can be utilized, the introduction of the water cooling system brings about the consumption of electric energy as the fan. In addition, the water cooling system generally has more pipelines and connection points, and is shorter in service life and lower in reliability in the face of extreme environments. Therefore, the current method for dissipating heat of the photovoltaic system has many defects.

In addition, the development of the photovoltaic industry is further hindered by hidden dangers such as corrosion, electric leakage and safety accidents caused by water vapor to the photovoltaic module.

Disclosure of Invention

The invention aims to provide a coating liquid for a photovoltaic module, a preparation method thereof and the photovoltaic module aiming at the defects of the prior art.

In order to solve the technical problems, the invention provides a coating liquid for a photovoltaic module, which comprises an alcohol solvent, and silica nanoparticles and vanadium dioxide @ silica nanoparticles dispersed in the alcohol solvent; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer.

Compared with the prior art, the invention has at least the following beneficial effects:

the coating liquid for the photovoltaic module comprises silicon dioxide nano particles and vanadium dioxide @ silicon dioxide nano particles, wherein the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer.

In one aspect, the vanadium dioxide in the vanadium dioxide @ silica nanoparticle core has the following characteristics: with the increase of the environmental temperature, the crystal structure of the vanadium dioxide is changed into a tetragonal rutile structure from a monoclinic structure, the monoclinic structure vanadium dioxide has high near-infrared transmittance, and the tetragonal rutile structure vanadium dioxide has high near-infrared reflectance. Therefore, after the coating liquid provided by the invention is adopted to form a coating on the surface of the photovoltaic module, the coating layer has higher near infrared transmittance in a low-temperature environment, and the utilization of near infrared light by a system is facilitated; and under high temperature environment, the coating film layer has lower near infrared transmittance, helps the reduction of system temperature to realized the near infrared automatic regulation and control characteristic of coating film layer, and then also made the photovoltaic module after the coating film have according to the function of operational environment temperature self-regulation light transmittance, avoided local high temperature to damage.

On the other hand, the shell surface of the vanadium dioxide @ silicon dioxide nano-particles is provided with a branch crystal structure, and after the coating liquid provided by the invention is adopted to form a coating on the surface of the photovoltaic module, when water vapor in an external environment enters the photovoltaic module through the coating layer, the water vapor is hindered by the branch crystal structure interwoven in the coating layer, so that the coating layer can effectively improve the waterproof performance of the photovoltaic module. Moreover, the branch crystal structure also increases the porosity of the coating layer, which is beneficial to improving the optical transmittance.

Preferably, in the coating solution for a photovoltaic module provided by the invention, the molar ratio of the silica nanoparticles to the vanadium dioxide @ silica nanoparticles is 1: 40-40: 1; preferably 1: 1-40: 1. by optimizing the molar ratio of the silicon dioxide nano-particles to the vanadium dioxide @ silicon dioxide nano-particles, the coating layer can realize the most suitable near infrared regulation and control capability and the best waterproof performance.

Preferably, in the coating liquid for the photovoltaic module provided by the invention, the particle diameters of the silicon dioxide nanoparticles and the vanadium dioxide @ silicon dioxide nanoparticles are respectively and independently 200-300 nanometers. The silicon dioxide nanoparticles and the vanadium dioxide @ silicon dioxide nanoparticles with the particle sizes of 200-300 nanometers are easy to prepare and obtain, and have stable physicochemical properties in the process of using the silicon dioxide nanoparticles and the vanadium dioxide @ silicon dioxide nanoparticles to prepare the coating liquid for the photovoltaic module.

Preferably, in the coating liquid for a photovoltaic module provided by the invention, the alcohol solvent is at least one selected from methanol, ethanol, propanol or isopropanol. The alcohol solvent can uniformly disperse and mix the silicon dioxide nano-particles and the vanadium dioxide @ silicon dioxide nano-particles in the coating liquid, thereby being beneficial to the coating operation and the uniform reliability of the coating layer.

The second aspect of the present invention provides a method for preparing a coating solution for a photovoltaic module, including the steps of: s1: preparation of vanadium dioxide @ silica nanoparticles: dissolving vanadium dioxide nanoparticles and a silicon precursor in an alcohol solvent, adding a dispersion system, stirring, placing in a hydrothermal reaction kettle, and reacting at 150-300 ℃ for 12-16 hours to obtain a dispersion system containing vanadium dioxide @ silicon dioxide nanoparticles; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer; s2: preparing a coating liquid for the photovoltaic module: and mixing the dispersion system containing the vanadium dioxide @ silicon dioxide nano particles with a coating liquid containing the silicon dioxide nano particles, or adding the silicon dioxide nano particles into the dispersion system containing the vanadium dioxide @ silicon dioxide nano particles to obtain the coating liquid for the photovoltaic module. The preparation method of the coating liquid for the photovoltaic module provided by the invention is simple and feasible in steps and controllable in process.

In the preparation method of the coating liquid for the photovoltaic module, the silicon precursor is selected from at least one of methyltrimethoxysilane, vinyl trimethoxysilane and tetraethoxysilane.

In the preparation method of the coating liquid for the photovoltaic module, the dispersion system is selected from one or more of the following solvent combinations: oxalic acid and ammonia, citric acid and ammonia, oxalic acid and sodium bicarbonate. The addition of the dispersion system can adjust the pH value of the system and fully disperse the reaction system.

The third aspect of the invention provides a photovoltaic module, which comprises a light-transmitting substrate and a coating layer arranged on the light-transmitting substrate, wherein the coating layer is formed by coating the photovoltaic module with the coating liquid of the first aspect of the invention.

In the photovoltaic module provided by the invention, the coating layer comprises silicon dioxide nanoparticles and vanadium dioxide @ silicon dioxide nanoparticles; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer.

In the photovoltaic module provided by the invention, the molar ratio of the silica nanoparticles to the vanadium dioxide @ silica nanoparticles is 1: 40-40: 1; preferably 1: 1-40: 1.

the photovoltaic module provided by the invention adopts the coating liquid of the first aspect of the invention for coating, thereby having the following characteristics: the transmittance in a visible light region is higher; in the near infrared region, the film has higher transmittance under the low temperature condition and higher reflectivity under the high temperature condition. The photovoltaic module provided by the invention has excellent optical absorption performance, can automatically adjust the absorption of near infrared light in high and low temperature environments, and has an autonomous temperature regulation characteristic; meanwhile, the waterproof coating has excellent waterproof performance and is beneficial to prolonging the service life of the photovoltaic module.

Drawings

FIG. 1 is a schematic structural diagram of vanadium dioxide @ silica nanoparticles according to an embodiment of the present invention;

fig. 2 is an SEM image of a photovoltaic module coating according to an embodiment of the present invention.

Detailed Description

In order that the objects, features and advantages of the present invention can be more clearly understood, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The materials used are not indicated by the manufacturer, and are all conventional products available by commercial purchase. The description of the exemplary embodiments is for exemplary purposes only and is not intended to limit the invention or its applications.

According to a first aspect of the invention, some embodiments of the invention provide a coating solution for a photovoltaic module, which comprises an alcohol solvent, and silica nanoparticles and vanadium dioxide @ silica nanoparticles dispersed in the alcohol solvent; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer.

In some embodiments of the invention, the mole ratio of silica nanoparticles to vanadium dioxide @ silica nanoparticles is 1: 40-40: 1

In some embodiments of the invention, the mole ratio of silica nanoparticles to vanadium dioxide @ silica nanoparticles is 1: 1-40: 1, so that the coating liquid has the most suitable near infrared regulation and control capability and the best waterproof performance.

In some embodiments of the present invention, the silica nanoparticles and the vanadium dioxide @ silica nanoparticles each independently have a particle size of 200 to 300 nanometers. The silicon dioxide nano-particles and the vanadium dioxide @ silicon dioxide nano-particles within the particle size range are easy to prepare and have stable physicochemical properties.

In some embodiments of the invention, the alcoholic solvent used to disperse the silica nanoparticles and vanadium dioxide @ silica nanoparticles is selected from at least one of methanol, ethanol, propanol, or isopropanol. The alcohol solvent can uniformly disperse and mix the silicon dioxide nano-particles and the vanadium dioxide @ silicon dioxide nano-particles in the coating liquid, thereby being beneficial to the coating operation and the uniform reliability of the coating layer.

Fig. 1 is a schematic structural diagram of the vanadium dioxide @ silica nanoparticle in the embodiment, and as shown in the figure, the structure is a core-shell structure in which a shell layer wraps a core, the core is vanadium dioxide, the shell layer is a silica layer, and silica branch crystals are arranged on the surface of the silica layer.

According to a second aspect of the present invention, some embodiments of the present invention provide a method for preparing a coating liquid for a photovoltaic module, including the steps of:

s1: preparation of vanadium dioxide @ silica nanoparticles: dissolving vanadium dioxide nanoparticles and a silicon precursor in an alcohol solvent, adding a dispersion system, stirring, placing in a hydrothermal reaction kettle, and reacting at 150-300 ℃ for 12-16 hours to obtain a dispersion system containing vanadium dioxide @ silicon dioxide nanoparticles; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are arranged on the surface of the silicon dioxide layer;

s2: preparing a coating liquid for the photovoltaic module: and mixing the dispersion system containing the vanadium dioxide @ silicon dioxide nano particles with a coating liquid containing the silicon dioxide nano particles, or adding the silicon dioxide nano particles into the dispersion system containing the vanadium dioxide @ silicon dioxide nano particles to obtain the coating liquid for the photovoltaic module.

In some embodiments of the present invention, the vanadium dioxide nanoparticles used in step S1 are commercially available or may be prepared by wet chemistry methods conventional in the art.

In some embodiments of the invention, the silicon precursor is selected from at least one of methyltrimethoxysilane, vinyltrimethoxysilane, and ethyl orthosilicate.

In some embodiments of the invention, the dispersion may be selected from at least one of the following solvent combinations: oxalic acid and ammonia, citric acid and ammonia, oxalic acid and sodium bicarbonate.

The preparation method of the coating liquid for the photovoltaic module provided by the embodiment of the invention has the advantages of simple and feasible steps and controllable process.

According to a third aspect of the present invention, some embodiments of the present invention provide a photovoltaic module, including a transparent substrate and a coating layer disposed on the transparent substrate, wherein the coating layer is formed by coating with the coating liquid for a photovoltaic module according to the first aspect of the present invention.

In some embodiments of the present invention, the method for coating a photovoltaic module with the coating solution of the present invention may be a dip-coating method, a blade-coating method or a spin-coating method, which are conventional in the art, and the coating is performed by coating on the glass surface or the transparent backplane surface of the photovoltaic module in a protective atmosphere.

According to the photovoltaic module provided by the embodiment of the invention, the coating layer is obtained by coating with the coating liquid provided by the first aspect of the invention, so that the coating layer contains silicon dioxide nanoparticles and vanadium dioxide @ silicon dioxide nanoparticles; the vanadium dioxide @ silicon dioxide nano particles are of a core-shell structure with a shell layer coating an inner core, the inner core is vanadium dioxide, the shell layer is a silicon dioxide layer, and silicon dioxide branch crystals are further attached to the surface of the silicon dioxide layer.

Fig. 2 is an SEM image of the photovoltaic module coating layer in the present embodiment, showing a microscopic view of the branch crystal structure in the coating layer.

In one aspect, the vanadium dioxide in the vanadium dioxide @ silica nanoparticle core has the following characteristics: with the increase of the environmental temperature, the crystal structure of the vanadium dioxide is changed into a tetragonal rutile structure from a monoclinic structure, the monoclinic structure vanadium dioxide has high near-infrared transmittance, and the tetragonal rutile structure vanadium dioxide has high near-infrared reflectance. Therefore, the coating layer has higher near infrared transmittance in a low-temperature environment, and is beneficial to the utilization of near infrared light by a system; the coating film layer has lower near-infrared transmittance under high temperature environment, and is helpful for reducing the system temperature, so that the coating film layer has the near-infrared automatic regulation and control characteristic, the photovoltaic module also has the function of self-regulating the light transmittance according to the working environment temperature, and the local high-temperature damage can be avoided.

On the other hand, the shell layer of the vanadium dioxide @ silicon dioxide nano particles is a silicon dioxide layer, a layer of silicon dioxide with a branch crystal structure is attached to the surface of the shell layer, and when water vapor enters the photovoltaic module from the coating layer, the water vapor is hindered by the branch crystal structure interwoven in the coating layer, so that the waterproof performance of the module can be effectively improved. Moreover, the branch crystal structure also increases the porosity of the coating layer, which is beneficial to improving the optical transmittance.

Therefore, the photovoltaic module provided by the embodiment of the invention has the following characteristics: the transmittance in a visible light region is higher; in the near infrared region, the film has higher transmittance under the low temperature condition and higher reflectivity under the high temperature condition. The photovoltaic module provided by the invention has excellent optical absorption performance, can automatically adjust the absorption of near infrared light in high and low temperature environments, and has an autonomous temperature regulation characteristic; meanwhile, the waterproof coating has excellent waterproof performance and is beneficial to prolonging the service life of the photovoltaic module.

The above examples are only for illustrating the technical idea and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the content of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.