Method for preparing electrochromic glass device

Abstract

The present invention belongs to the technical field of optical glass. More specifically, it relates to a method for preparing an electrochromic glass device. The specific preparation steps of the present invention include: after cleaning the surface of the glass substrate, using magnetron sputtering to deposit a transparent conductive layer of indium tin oxide on the surface of the glass substrate; using nano-spherical silica as a template, dispersing it in an ethanol solution, then adding a sodium tungstate solution, then adjusting the pH to 2-3, stirring the reaction, and washing with a sodium hydroxide solution to remove the template to obtain a hollow spherical precursor dispersion; applying the hollow spherical precursor dispersion on the surface of the transparent conductive layer by spin coating, drying, and annealing; configuring the liquid electrolyte: using propylene carbonate as a solvent and lithium perchlorate as an electrolyte lithium salt; depositing NiO as a counter electrode on the surface of the WO3 electrochromic layer by magnetron sputtering; using epoxy resin to encapsulate the edge, injecting the liquid electrolyte, and then hot pressing to remove the residual bubbles inside to obtain the product.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical glass and more specifically relates to a method for preparing an electrochromic glass device. Background Art

[0002] Electrochromic glass is a type of smart glass that changes its optical properties (such as transmittance, reflectance, or color) by applying a voltage. Its core characteristic is its ability to reversibly adjust light transmittance under the influence of an applied electric field, thereby achieving energy savings, privacy protection, and optimized visual comfort.

[0003] Electrochromic glass typically consists of a multilayer thin-film structure, including an electrochromic layer (such as WO3), an ion conductor layer (electrolyte), and an ion storage layer (such as NiO). When a small voltage (typically 1-5V) is applied, lithium ions (Li⁺) or protons (H⁺) migrate between the layers, triggering a redox reaction that changes the optical properties of the electrochromic layer. By varying the voltage or the material combination (such as conductive polymers), different colors (blue, gray, green, etc.) and transmittance levels (typically adjustable from 5% to 80%) can be achieved.

[0004] In the field of electrochromic glass devices, for example, patent CN112817189A uses a gel electrolyte as an ion transport medium to improve the color change efficiency by increasing the ion conductivity. However, there is still a problem of uniformity in the preparation process, which is mainly manifested in uneven color change response, different color depths or local defects, which directly affects the performance and aesthetics of the device. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that existing electrochromic glass devices suffer from uneven color change during use, and local defects become more severe as the product's service life increases. To address these challenges, the present invention provides a method for preparing an electrochromic glass device.

[0006] The purpose of the present invention is to provide a method for preparing an electrochromic glass device.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing an electrochromic glass device, the specific preparation steps comprising:

[0009] Transparent conductive layer deposition:

[0010] After cleaning the surface of the glass substrate, a transparent conductive layer of indium tin oxide is deposited on the surface of the glass substrate by magnetron sputtering;

[0011] Preparation of WO3 electrochromic layer:

[0012] Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 2-3. After stirring for reaction, the mixture is washed with a sodium hydroxide solution to remove the template, thereby obtaining a hollow spherical precursor dispersion.

[0013] Spin coating the hollow spherical precursor dispersion on the surface of the transparent conductive layer, drying, and annealing;

[0014] Liquid electrolyte configuration:

[0015] Propylene carbonate was used as solvent and lithium perchlorate was used as electrolyte lithium salt with a concentration of 1 mol / L;

[0016] Preparation of the counter electrode:

[0017] NiO was deposited on the surface of the WO3 electrochromic layer by magnetron sputtering as a counter electrode;

[0018] The thickness of the counter electrode is 60-70% of the thickness of the WO3 electrochromic layer;

[0019] Package:

[0020] The edges are encapsulated with epoxy resin, and after liquid electrolyte is injected, hot pressing is performed to remove residual bubbles inside to obtain the product.

[0021] The technical effects of the above technical solution are:

[0022] The above technical solution uses nano-spherical silica as a template during the preparation of the WO3 electrochromic layer. Nano-spherical silica has a high surface energy and adsorption-active Si-OH functional groups. During the hydrolysis of sodium tungstate solution to produce a precursor, it can be adsorbed and fixed on the surface of the nano-silica, and its spherical structure ensures the uniformity of adsorption. Subsequently, sodium hydroxide is used as an etching solution to remove the core template nano-spherical silica, thereby obtaining a hollow spherical precursor. In the subsequent annealing process, it is finally transformed into a hollow spherical WO3. The hollow structure of WO3 can significantly reduce the ion diffusion distance compared to a solid sphere due to its thin shell, thereby alleviating the response difference caused by the uneven ion migration rate at the surface and the center. In addition, during the cycle, WO3 will undergo a certain volume change. The presence of the hollow structure can alleviate the volume change and reduce the conductive network breakage caused by particle rupture, thereby maintaining long-term uniformity. Furthermore, the internal space can store electrolytes, thereby improving the infiltration effect.

[0023] Furthermore, the D50 of the nano-spherical silica is 30-35 nm; the particle size distribution range is 10-60 nm; and the sphericity is 0.88-0.92.

[0024] The above technical solution further regulates the specifications of the template silica, including the average particle size and particle size distribution, as well as the sphericity, thereby regulating the size and sphericity of the hollow spherical WO3 formed by adsorption on its surface.

[0025] Furthermore, the preparation of the WO3 electrochromic layer further includes:

[0026] Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 2-3. After stirring for reaction, the mixture is washed with a sodium hydroxide solution to remove the template, thereby obtaining a hollow spherical precursor dispersion.

[0027] The amount of the nano-spherical silica is 20-25% of the mass of the ethanol solution;

[0028] The mass fraction of the sodium tungstate solution is 18-20%, and the amount of the sodium tungstate solution is 3.5-4.0 times the mass of the nano-spherical silica;

[0029] The hollow spherical precursor dispersion is coated on the surface of the transparent conductive layer by spin coating, dried, and annealed.

[0030] Furthermore, the preparation of the WO3 electrochromic layer further includes:

[0031] The hollow spherical precursor dispersion is applied to the surface of the transparent conductive layer by spin coating, and the wet film thickness is controlled to be 70-80 nm. After drying, the hollow spherical precursor dispersion is applied to the surface of the transparent conductive layer again by spin coating, and the wet film thickness is controlled to be 40-50 nm. After drying, annealing is performed at a temperature of 340-360°C for 60-70 minutes.

[0032] Furthermore, the preparation of the WO3 electrochromic layer further includes:

[0033] Nano-spherical silica is used as a template and dispersed in an ethanol solution. Sodium tungstate solution is then added, and the pH is adjusted to 2-3. After stirring for reaction, the template is removed by washing with a sodium hydroxide solution. A water-soluble aluminum salt solution is then added, and the pH is adjusted to 7.0-7.2. After stirring for reaction, a hollow spherical precursor dispersion is obtained.

[0034] Furthermore, the mass fraction of the water-soluble aluminum salt solution is 10-12%;

[0035] Furthermore, the amount of the water-soluble aluminum salt solution is 12-15% of the mass of the sodium tungstate solution;

[0036] The water-soluble aluminum salt solution is selected from any one of aluminum chloride solution, aluminum sulfate solution, and aluminum nitrate solution.

[0037] The beneficial effects of the above technical solution include:

[0038] The above technical solution coats the WO3 surface with an alumina coating layer. On the one hand, alumina can reduce the side reaction between WO3 and the electrolyte, thereby improving the cycle stability and maintaining the long-term uniformity of the product; on the other hand, the thickness of the alumina coating on the WO3 surface can be further regulated by adjusting the amount of alumina raw material, thereby adjusting the surface charge distribution through the interfacial polarization effect and improving the uniformity of the surface electric field.

[0039] Furthermore, the liquid electrolyte further includes polymethyl methacrylate as a thickener in an amount of 3-5% by mass of the propylene carbonate.

[0040] Furthermore, the package further includes:

[0041] The edge is encapsulated with epoxy resin, and after liquid electrolyte is injected, hot pressing is performed for 3-5 minutes at a temperature of 60-62°C and a pressure of 0.5-0.6MPa to remove residual bubbles inside to obtain the product. DETAILED DESCRIPTION

[0042] The present invention is further described below with reference to specific examples, which, however, are not intended to limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0043] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0044] Example 1

[0045] Transparent conductive layer deposition:

[0046] Ordinary glass was used as a substrate and its surface was cleaned. Specifically, ultrasonic cleaning was performed with acetone, ethanol, and deionized water for 12 minutes each at an ultrasonic frequency of 60 kHz. After cleaning, oxygen plasma was used at a power of 100 W for 5 minutes. Subsequently, a transparent conductive layer of indium tin oxide with a thickness of 200 nm was deposited on the surface of the glass substrate by magnetron sputtering using In2O3-SnO2 (90:10 wt%) as a target under the conditions of Ar gas pressure of 0.5 Pa, power of 100 W, substrate temperature of 300°C, and deposition rate of 10 nm / min.

[0047] Preparation of WO3 electrochromic layer:

[0048] Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 2. After stirring and reacting, the template is washed with a sodium hydroxide solution to remove the template. A water-soluble aluminum salt solution is then added, and the pH is adjusted to 7.0. After stirring and reacting, a hollow spherical precursor dispersion is obtained.

[0049] The nano-spherical silica has a D50 of 30 nm, a particle size distribution range of 10-60 nm, and a sphericity of 0.88.

[0050] The amount of the nano-spherical silica is 20% of the mass of the ethanol solution;

[0051] The mass fraction of the sodium tungstate solution is 18%, and the amount of the sodium tungstate solution is 3.5 times the mass of the nano-spherical silica;

[0052] The mass fraction of the water-soluble aluminum salt solution is 10%;

[0053] Furthermore, the amount of the water-soluble aluminum salt solution is 12% of the mass of the sodium tungstate solution;

[0054] The water-soluble aluminum salt solution is selected from: aluminum chloride solution;

[0055] The hollow sphere precursor dispersion was applied to the surface of the transparent conductive layer by spin coating, with a wet film thickness of 70 nm. After drying, the hollow sphere precursor dispersion was applied to the surface of the transparent conductive layer again by spin coating, with a wet film thickness of 40 nm. After drying, the layer was annealed at 340°C for 60 min.

[0056] Liquid electrolyte configuration:

[0057] Propylene carbonate is used as a solvent, lithium perchlorate is used as an electrolyte lithium salt, the concentration is 1 mol / L, and polymethyl methacrylate (PMMA) is added as a thickener at a concentration of 3% by weight of the propylene carbonate;

[0058] Preparation of the counter electrode:

[0059] NiO was deposited on the surface of the WO3 electrochromic layer by magnetron sputtering as a counter electrode;

[0060] The thickness of the counter electrode is 60% of the thickness of the WO3 electrochromic layer;

[0061] Package:

[0062] The edges were encapsulated with epoxy resin, and after liquid electrolyte was injected, hot pressing was performed at a temperature of 60°C and a pressure of 0.5 MPa for 3 minutes to remove residual bubbles inside to obtain the product.

[0063] Example 2

[0064] Transparent conductive layer deposition:

[0065] Ordinary glass was used as a substrate and its surface was cleaned. Specifically, ultrasonic cleaning was performed with acetone, ethanol, and deionized water for 12 minutes each at an ultrasonic frequency of 60 kHz. After cleaning, oxygen plasma was used at a power of 100 W for 5 minutes. Subsequently, a transparent conductive layer of indium tin oxide with a thickness of 200 nm was deposited on the surface of the glass substrate by magnetron sputtering using In2O3-SnO2 (90:10 wt%) as a target under the conditions of Ar gas pressure of 0.5 Pa, power of 100 W, substrate temperature of 300°C, and deposition rate of 10 nm / min.

[0066] Preparation of WO3 electrochromic layer:

[0067] Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 2.5. After stirring and reacting, the template is washed with a sodium hydroxide solution to remove the template. A water-soluble aluminum salt solution is then added, and the pH is adjusted to 7.1. After stirring and reacting, a hollow spherical precursor dispersion is obtained.

[0068] The nano-spherical silica has a D50 of 32 nm, a particle size distribution range of 10-60 nm, and a sphericity of 0.9.

[0069] The amount of the nano-spherical silica is 22% of the mass of the ethanol solution;

[0070] The mass fraction of the sodium tungstate solution is 19%, and the amount of the sodium tungstate solution is 3.8 times the mass of the nano-spherical silica;

[0071] The mass fraction of the water-soluble aluminum salt solution is 11%;

[0072] Furthermore, the amount of the water-soluble aluminum salt solution is 14% of the mass of the sodium tungstate solution;

[0073] The water-soluble aluminum salt solution is selected from: aluminum sulfate solution;

[0074] The hollow sphere precursor dispersion was applied to the surface of the transparent conductive layer by spin coating, with a wet film thickness of 75 nm. After drying, the hollow sphere precursor dispersion was applied to the surface of the transparent conductive layer again by spin coating, with a wet film thickness of 45 nm. After drying, the layer was annealed at 350°C for 65 min.

[0075] Liquid electrolyte configuration:

[0076] Propylene carbonate is used as a solvent, lithium perchlorate is used as an electrolyte lithium salt, the concentration is 1 mol / L, and polymethyl methacrylate (PMMA) is added as a thickener at a concentration of 4% by weight of the propylene carbonate;

[0077] Preparation of the counter electrode:

[0078] NiO was deposited on the surface of the WO3 electrochromic layer by magnetron sputtering as a counter electrode;

[0079] The thickness of the counter electrode is 65% of the thickness of the WO3 electrochromic layer;

[0080] Package:

[0081] The edges were encapsulated with epoxy resin, and after liquid electrolyte was injected, hot pressing was performed at a temperature of 61°C and a pressure of 0.55 MPa for 4 minutes to remove residual bubbles inside, thereby obtaining the product.

[0082] Example 3

[0083] Transparent conductive layer deposition:

[0084] Ordinary glass was used as a substrate and its surface was cleaned. Specifically, ultrasonic cleaning was performed with acetone, ethanol, and deionized water for 12 minutes each at an ultrasonic frequency of 60 kHz. After cleaning, oxygen plasma was used at a power of 100 W for 5 minutes. Subsequently, a transparent conductive layer of indium tin oxide with a thickness of 200 nm was deposited on the surface of the glass substrate by magnetron sputtering using In2O3-SnO2 (90:10 wt%) as a target under the conditions of Ar gas pressure of 0.5 Pa, power of 100 W, substrate temperature of 300°C, and deposition rate of 10 nm / min.

[0085] Preparation of WO3 electrochromic layer:

[0086] Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 3. After stirring and reacting, the template is washed with a sodium hydroxide solution to remove the template. A water-soluble aluminum salt solution is then added, and the pH is adjusted to 7.2. After stirring and reacting, a hollow spherical precursor dispersion is obtained.

[0087] The nano-spherical silica has a D50 of 35 nm, a particle size distribution range of 10-60 nm, and a sphericity of 0.92.

[0088] The amount of the nano-spherical silica is 25% of the mass of the ethanol solution;

[0089] The mass fraction of the sodium tungstate solution is 20%, and the amount of the sodium tungstate solution is 4.0 times the mass of the nano-spherical silica;

[0090] The mass fraction of the water-soluble aluminum salt solution is 12%;

[0091] Furthermore, the amount of the water-soluble aluminum salt solution is 15% of the mass of the sodium tungstate solution;

[0092] The water-soluble aluminum salt solution is selected from: aluminum nitrate solution;

[0093] The hollow sphere precursor dispersion was applied to the surface of the transparent conductive layer by spin coating to control the wet film thickness to 80 nm. After drying, the hollow sphere precursor dispersion was applied to the surface of the transparent conductive layer again by spin coating to control the wet film thickness to 50 nm. After drying, the layer was annealed at 360°C for 70 min.

[0094] Liquid electrolyte configuration:

[0095] Propylene carbonate is used as a solvent, lithium perchlorate is used as an electrolyte lithium salt, the concentration is 1 mol / L, and polymethyl methacrylate (PMMA) is added as a thickener at a concentration of 5% by weight of the propylene carbonate;

[0096] Preparation of the counter electrode:

[0097] NiO was deposited on the surface of the WO3 electrochromic layer by magnetron sputtering as a counter electrode;

[0098] The thickness of the counter electrode is 70% of the thickness of the WO3 electrochromic layer;

[0099] Package:

[0100] The edges were encapsulated with epoxy resin, and after liquid electrolyte was injected, hot pressing was performed at a temperature of 62°C and a pressure of 0.6 MPa for 5 minutes to remove residual bubbles inside, thereby obtaining the product.

[0101] Example 4

[0102] Compared with Example 1, this embodiment differs in that no water-soluble aluminum salt solution is added, and other conditions remain unchanged.

[0103] Example 5

[0104] Compared with Example 1, the present embodiment differs in that: the D50 of the nano-spherical silica is 30 nm; the particle size distribution range is 1-120 nm; and the sphericity is 0.8, and the other conditions remain unchanged.

[0105] Comparative Example 1

[0106] The difference between this comparative example and Example 1 is that no nano-spherical silica is added, and the other conditions remain unchanged.

[0107] The performance tests of the products obtained in the above examples and comparative examples were carried out, and the specific test methods and test results are shown below:

[0108] Refer to GB / T 18915.2 (Electrochromic Glass Performance Test) standard to test the product response time distribution. Apply a step voltage (±3 V) and record the time required for each area to reach 90% ΔT, which is τ 90 ;

[0109] The above-described examples and comparative examples were subjected to accelerated aging tests at 60°C using a Gamry Interface 5000 electrochemical workstation, with a square wave pulse voltage waveform (±3.0 V, frequency 0.01-0.1 Hz). Other test conditions followed IEC 62805-1: Durability Test Method for Electrochromic Devices. After 500 cycles, the response time distribution of the products was tested again according to GB / T 18915.2 (Electrochromic Glass Performance Test) to determine the time required for each region to reach 90% of ΔT after cycling.

[0110] The specific test results are shown in Table 1;

[0111] ;

[0112] As can be seen from the test results in Table 1, the product obtained by the present invention not only has a faster overall response time, but also has a smaller difference in response time between the central area and the edge area. In particular, after long-term accelerated aging cycle experiments, it can still maintain a good response effect.

[0113] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing an electrochromic glass device, characterized in that: The specific preparation steps include: Transparent conductive layer deposition: After cleaning the surface of the glass substrate, a transparent conductive layer of indium tin oxide is deposited on the surface of the glass substrate by magnetron sputtering; Preparation of WO3 electrochromic layer: Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 2-3. After stirring for reaction, the mixture is washed with a sodium hydroxide solution to remove the template, thereby obtaining a hollow spherical precursor dispersion. Spin coating the hollow spherical precursor dispersion on the surface of the transparent conductive layer, drying, and annealing; Liquid electrolyte configuration: Propylene carbonate was used as solvent and lithium perchlorate was used as electrolyte lithium salt with a concentration of 1 mol / L; Preparation of the counter electrode: NiO was deposited on the surface of the WO3 electrochromic layer by magnetron sputtering as a counter electrode; The thickness of the counter electrode is 60-70% of the thickness of the WO3 electrochromic layer; Package: The edges are encapsulated with epoxy resin, and after liquid electrolyte is injected, hot pressing is performed to remove residual bubbles inside to obtain the product.

2. The method for preparing an electrochromic glass device according to claim 1, wherein: The D50 of the nano-spherical silica is 30-35 nm; the particle size distribution range is 10-60 nm; and the sphericity is 0.88-0.

92.

3. The method for preparing an electrochromic glass device according to any one of claims 1 or 2, characterized in that: The preparation of the WO3 electrochromic layer further comprises: Nano-spherical silica is used as a template and dispersed in an ethanol solution. A sodium tungstate solution is then added, and the pH is adjusted to 2-3. After stirring for reaction, the mixture is washed with a sodium hydroxide solution to remove the template, thereby obtaining a hollow spherical precursor dispersion. The amount of the nano-spherical silica is 20-25% of the mass of the ethanol solution; The mass fraction of the sodium tungstate solution is 18-20%, and the amount of the sodium tungstate solution is 3.5-4.0 times the mass of the nano-spherical silica; The hollow spherical precursor dispersion is coated on the surface of the transparent conductive layer by spin coating, dried, and annealed.

4. The method for preparing an electrochromic glass device according to claim 3, wherein: The preparation of the WO3 electrochromic layer further comprises: The hollow spherical precursor dispersion is applied to the surface of the transparent conductive layer by spin coating, and the wet film thickness is controlled to be 70-80 nm. After drying, the hollow spherical precursor dispersion is applied to the surface of the transparent conductive layer again by spin coating, and the wet film thickness is controlled to be 40-50 nm. After drying, annealing is performed at a temperature of 340-360°C for 60-70 minutes.

5. The method for preparing an electrochromic glass device according to claim 3, wherein: The preparation of the WO3 electrochromic layer further comprises: Nano-spherical silica is used as a template and dispersed in an ethanol solution. Sodium tungstate solution is then added, and the pH is adjusted to 2-3. After stirring for reaction, the template is removed by washing with a sodium hydroxide solution. A water-soluble aluminum salt solution is then added, and the pH is adjusted to 7.0-7.

2. After stirring for reaction, a hollow spherical precursor dispersion is obtained.

6. The method for preparing an electrochromic glass device according to claim 5, characterized in that: The mass fraction of the water-soluble aluminum salt solution is 10-12%; Furthermore, the amount of the water-soluble aluminum salt solution is 12-15% of the mass of the sodium tungstate solution; The water-soluble aluminum salt solution is selected from any one of aluminum chloride solution, aluminum sulfate solution, and aluminum nitrate solution.

7. The method for preparing an electrochromic glass device according to claim 1, wherein: The liquid electrolyte further includes polymethyl methacrylate as a thickener in an amount of 3-5% by mass of the propylene carbonate.

8. The method for preparing an electrochromic glass device according to claim 1, wherein: The package further comprises: The edge is encapsulated with epoxy resin, and after liquid electrolyte is injected, hot pressing is performed for 3-5 minutes at a temperature of 60-62°C and a pressure of 0.5-0.6MPa to remove residual bubbles inside to obtain the product.