Functional ink for WO3-based electrochromic dimming glass, and preparation method and application thereof

Abstract

The invention discloses functional ink for WO3-based electrochromic dimming glass as well as a preparation method and application of the functional ink. The functional ink comprises Ti-doped WO3 particles and an auxiliary agent, the auxiliary agent comprises alcohol and a conductive high-molecular polymer, and the conductive high-molecular polymer comprises PEDOT: PSS and / or PEDOT. According to the functional ink for the WO3-based electrochromic dimming glass, Ti doping is introduced, so that the stability of a precursor solution is improved, the precursor solution can stably exist at room temperature for a long time, the validity period of the ink is prolonged, and the electrochromic performance of a film is further enhanced through Ti doping; alcohol and a conductive high-molecular polymer are adopted as auxiliaries, so that the obtained functional ink has moderate surface tension and viscosity, and the film-forming property of the ink is improved. The functional ink can be combined with a coating technology to realize large-size low-temperature preparation of a WO3 electrochromic film.

Description

TECHNICAL FIELD

[0001] The present application relates to a functional ink, in particular to a functional ink for WO3-based electrochromic light control glass, a preparation method and application thereof, and belongs to the technical field of electrochromic devices. BACKGROUND

[0002] Large-area electrochromic light control glass has a wide application prospect in the field of energy-saving building glass, automobile glass, etc. At present, the electrochromic light control glass is usually manufactured by physical vapor deposition (PVD), including vacuum evaporation technologies such as magnetron sputtering and thermal evaporation. Even though these technologies have the advantages of precise control of film thickness and easy adjustment of performance, there are still problems such as low manufacturing efficiency, high cost and limited large-area preparation, which hinder its practical application. Therefore, developing efficient, low-cost and large-area manufacturing technology has become a key technical problem to be solved. At present, the spin coating method through the solution process to prepare large-size electrochromic film layer has become one of the candidate technologies, but this method is difficult to guarantee the safety of the rapid rotation of the large-size substrate and the uniformity of the thickness of the large-area WO3-based film. Moreover, the spin coating method for preparing electrochromic film layer is usually limited to conventional hard substrates such as glass, and is greatly limited to flexible substrates such as PET. In fact, WO3 and hydrated WO3 electrochromic film layers of solution process are also considered as one of the candidate materials, but they may crack during service, resulting in degradation of electrochromic performance. Coating technology is considered to be a relatively simple, relatively low-cost, more easily expanded to large-area coating, suitable for various substrates and material types of thin film preparation technology. In order to improve the electrochromic performance and improve the product yield, the electrochromic light control glass manufacturing process usually needs a high-temperature process or a high-temperature post-processing process. For example, one existing method provides a method for preparing a WO3 precursor solution based on sol-gel method, and a WO3 thin film is deposited on an ITO glass substrate by spin coating technology. The deposited film is dried at 60°C for 2 hours. Then it is annealed at high temperature for 1 hour and naturally cooled to room temperature. The thin film has an amorphous structure after annealing at 250°C, showing moderate electrochemical stability and electrochromic performance, with a maximum optical modulation of 58.5% at a wavelength of 550 nm. However, the disadvantages of this method are the need for high-temperature post-processing and low optical modulation. Another existing method provides a method for preparing a WO3 precursor by sol-gel method, and a WO3 thin film is prepared on ITO and FTO glass substrates by self-spin coating, respectively. The thin film is then further annealed in an environment at 250°C. Then the electrochromic device is assembled with FTO and ITO as the counter electrode, respectively, and the coloring transmittance is 14% and the bleaching transmittance is 56% under a driving voltage of ±3V, with an optical modulation rate of 42%. The highest coloring efficiency is 72.53 cm 2 C- 1However, this method has drawbacks such as the need for high-temperature post-processing, low fading transmittance, and high driving voltage, which lead to excessively high process costs and make it difficult to apply flexible dimming glass.

[0003] Currently, there is a lack of functional ink processes and formulations suitable for large-area low-temperature coating technology for WO3-based electrochromic color-changing glass, which greatly restricts its practical application. Summary of the Invention

[0004] The main objective of this invention is to provide a functional ink for WO3-based electrochromic color-changing glass and its preparation method, so as to overcome the shortcomings of the prior art.

[0005] Another object of the present invention is to provide the application of the functional ink for WO3-based electrochromic color-changing glass.

[0006] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0007] This invention provides a functional ink for WO3-based electrochromic color-changing glass, comprising: Ti-doped WO3 particles and additives, wherein the additives include alcohols and conductive polymers, and the conductive polymers include PEDOT:PSS and / or PEDOT.

[0008] This invention also provides a method for preparing a functional ink for WO3-based electrochromic color-changing glass, comprising:

[0009] Tungsten was fully contacted with hydrogen peroxide to carry out an oxidation reaction, and then a titanium source was added for doping treatment to obtain a Ti-doped WO3 precursor.

[0010] The Ti-doped WO3 precursor is heated and then mixed with an alcohol and a conductive polymer to prepare a functional ink for WO3-based electrochromic color-changing glass. The conductive polymer includes PEDOT:PSS and / or PEDOT.

[0011] This invention also provides a functional ink for WO3-based electrochromic color-changing glass prepared by the aforementioned method.

[0012] This invention also provides the application of the aforementioned functional ink for WO3-based electrochromic light-emitting glass in the preparation of WO3-based electrochromic light-emitting glass or WO3 electrochromic thin film.

[0013] Accordingly, this invention also provides a method for preparing a WO3 electrochromic thin film, which includes: applying the functional ink for WO3-based electrochromic light-diffusing glass onto a substrate through a coating process to form a WO3 electrochromic thin film.

[0014] Accordingly, embodiments of the present invention also provide WO3 electrochromic thin films prepared by the aforementioned preparation method.

[0015] Compared with the prior art, the beneficial effects of the present invention include:

[0016] 1) The preparation method of the functional ink for WO3-based electrochromic photochromic glass provided by this invention is simple, requiring no reaction under high temperature and high pressure. The introduction of Ti doping improves the stability of the precursor solution, allowing it to remain stable at room temperature for a long time, thus extending the ink's shelf life. Ti doping also further enhances the electrochromic properties of the film. Using alcohol and PEDOT or PEDOT:PSS as additives gives the functional ink moderate surface tension and viscosity, improving its film-forming properties.

[0017] 2) The functional ink for WO3-based electrochromic color-changing glass provided by this invention has a simple composition and good stability. It is suitable for coating technology to prepare electrochromic films. The film has good electrochromic properties without high-temperature annealing treatment, providing an effective solution for low-cost, low-temperature, large-area preparation of electrochromic films.

[0018] 3) The functional ink for WO3-based electrochromic color-changing glass provided by this invention can be combined with coating technology to achieve large-size low-temperature preparation of WO3 electrochromic films. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a particle size distribution diagram of Ti-doped WO3 particles in the functional ink prepared in Example 1 of the present invention;

[0021] Figure 2a , Figure 2b The images show surface and cross-sectional SEM images of WO3 electrochromic films prepared by coating technology based on the functional ink prepared in Example 1 of this invention.

[0022] Figure 3a , Figure 3b AFM images of the surface of the ITO / glass substrate and the surface of the thin film based on the ITO / glass substrate in Embodiment 1 of the present invention, respectively;

[0023] Figure 4a , Figure 4b ,Figure 4c These are, respectively, the XRD pattern of the thin film based on ITO / glass substrate and the HRTEM image of the thin film based on ITO / glass substrate in Embodiment 1 of the present invention;

[0024] Figure 5a , Figure 5b , Figure 5c The images show the XPS spectra of W 4f, Ti 2p, and O 1s on the surface of the thin film based on ITO / glass substrate in Example 1 of this invention.

[0025] Figure 6a This is a transmittance curve of the thin film based on ITO / glass substrate in the fading state (+1.0V) and the colored state (-1.0V) in Example 1 of the present invention;

[0026] Figure 6b This is an in-situ transmittance curve of the ITO / glass substrate thin film in Example 1 of the present invention at a wavelength of 633nm under a voltage range of -1.0V (20s) to +1.0V (20s);

[0027] Figure 6c This is a graph showing the in-situ optical density versus charge density of the thin film based on ITO / glass substrate in Embodiment 1 of the present invention.

[0028] Figure 6d This is a graph showing the results of a long-cycle test of 1000 cycles on a thin film based on an ITO / glass substrate in Example 1 of the present invention.

[0029] Figure 7a The image shows the SEM image of the thin film obtained in Comparative Example 1.

[0030] Figure 7b The image shows the HRTEM image of the thin film obtained in Comparative Example 1.

[0031] Figure 7c The image shows the AFM test results of the thin film obtained in Comparative Example 1.

[0032] Figure 7d The coloring and fading spectra of the thin film obtained in Comparative Example 1 in the wavelength range of 320–1000 nm are shown.

[0033] Figure 7e The in-situ transmittance spectrum of the thin film obtained in Comparative Example 1 at a wavelength of 633 nm within a voltage range of -1.0 V (20 s) to +1.0 V (20 s) is shown.

[0034] Figure 7f The graph shows the variation of in-situ optical density with charge density of the thin film obtained in Comparative Example 1.

[0035] Figure 7gThe graph shows the test results of 20 cycles for the thin film prepared in Comparative Example 1. Detailed Implementation

[0036] In view of the shortcomings of the existing technology, after long-term research and a large number of experiments, the inventors of this case proposed this technical solution, which mainly developed a new type of functional ink for WO3-based electrochromic color-changing glass, and combined with coating technology to realize the low-temperature preparation of amorphous embedded nanocrystal WO3-based electrochromic thin film.

[0037] The following will provide a further explanation of the technical solution, its implementation process, and its principles.

[0038] The following terms require explanation:

[0039] Electrochromism: Electrochromism (EC) refers to the phenomenon that the optical properties (absorption / transmittance / reflectance) of certain materials can undergo reversible changes under the action of an applied electric field.

[0040] Functional inks: Inks with specific functions or properties, primarily designed to meet specific application requirements. Compared to traditional inks, functional inks typically possess more specialized properties that can be used to achieve certain functions.

[0041] As one aspect of the technical solution of the present invention, a functional ink for WO3-based electrochromic color-changing glass includes: Ti-doped WO3 particles and additives, wherein the additives include alcohols and conductive polymers.

[0042] In some embodiments, the conductive polymer may include PEDOT, or PEDOT:PSS may be used instead of PEDOT.

[0043] In some implementations, the alcohol may be ethanol, isopropanol, etc., but is not limited to these.

[0044] In some embodiments, the functional ink contains 5-20 wt% Ti-doped WO3 particles, 10-20 wt% alcohol, and 2-10 wt% conductive polymer.

[0045] In some embodiments, the Ti-doped WO3 particles have a particle size of 3–30 nm.

[0046] Furthermore, the Ti doping amount in the Ti-doped WO3 particles is 2–6 wt%.

[0047] Furthermore, the Ti-doped WO3 particles have an amorphous embedded nanocrystalline structure.

[0048] As another aspect of the technical solution of this invention, it relates to a method for preparing a functional ink for WO3-based electrochromic color-changing glass, comprising:

[0049] Tungsten was fully contacted with hydrogen peroxide to carry out an oxidation reaction, and then a titanium source was added for doping treatment to obtain a Ti-doped WO3 precursor solution.

[0050] The Ti-doped WO3 precursor solution is heated and then mixed with an alcohol and a conductive polymer to prepare a functional ink for WO3-based electrochromic color-changing glass. The conductive polymer includes PEDOT:PSS and / or PEDOT.

[0051] In some specific implementations, the mass-to-volume ratio of tungsten to hydrogen peroxide is (0.1-2) g : (30-60) ml.

[0052] Furthermore, the tungsten used in this invention is tungsten powder, such as nano-tungsten powder.

[0053] In some specific implementations, the oxidation reaction is carried out at room temperature for 20–30 hours.

[0054] Furthermore, the preparation method further includes: after the oxidation reaction is completed, filtering, and heating the obtained filtrate at 60-100°C for 20-60 minutes to ensure that the unreacted hydrogen peroxide is completely decomposed.

[0055] In some specific embodiments, the titanium source may include tetrabutyl titanate, or it may be titanium tetraisopropoxide (Ti(O)2)2. i Pr)4), Tetraisopropyl di(dioctylphosphite)titanate (C 44 H 98 O 10 Any one or more combinations of P2Ti, etc., but not limited to these.

[0056] The preparation method of this invention employs a one-step solution method to prepare the tungsten oxide precursor solution, eliminating the need for high-temperature and high-pressure reactions and simplifying the preparation process. In a system with WO3 as the main material, the introduction of Ti doping improves the stability of the precursor solution, allowing it to remain stable at room temperature for extended periods. This solves the problem of WO3 precursor solutions easily precipitating and failing, thus extending the shelf life of the ink. Furthermore, Ti doping induces the formation of an amorphous structure intercalated with nanocrystals, further enhancing the electrochromic properties of the film.

[0057] Furthermore, the titanium source accounts for 3-6% of the volume fraction of the aforementioned filtrate;

[0058] Furthermore, the Ti-doped WO3 precursor solution is heated to a temperature of 60–100°C for a time of 60–120 min, thereby evaporating part of the solvent and byproducts of the titanium source, such as butanol, a byproduct of the decomposition of tetrabutyl titanate.

[0059] In some specific embodiments, the alcohol added in this invention accounts for 5-30% of the volume fraction of the Ti-doped WO3 precursor solution. The alcohol added in this invention is preferably anhydrous ethanol. Anhydrous ethanol, as an additive, can improve the wettability of functional inks and increase their applicability to different substrates. Specifically, the mechanism of ethanol as an additive is that ethanol is a polar solvent and can form hydrogen bonds with water molecules, thereby reducing the surface tension of water. When ethanol is mixed with water, ethanol molecules interact with water molecules, disrupting the hydrogen bond network between water molecules, thus reducing the surface tension of the ink.

[0060] In some specific embodiments, the conductive polymer added in this invention accounts for 4-8% of the volume fraction of the Ti-doped WO3 precursor solution. The addition of conductive polymers such as PEDOT, PSS, etc., as additives improves the viscosity of the functional ink and enhances its conductivity. Specifically, taking PEDOT as an example, the mechanism of using conductive polymers as additives is that high-viscosity PEDOT can increase the viscosity of the ink and improve the film uniformity. During the coating process, high-viscosity ink can better adhere to the substrate surface, forming a uniform film. Furthermore, high-viscosity ink can reduce ink flow on the substrate surface, avoiding ink accumulation or unevenness.

[0061] In some preferred embodiments, a method for preparing a functional ink for WO3-based electrochromic color-changing glass specifically includes the following steps:

[0062] A one-step solution method was used to prepare the Ti-doped WO3 precursor solution: First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 0.1–2 g tungsten powder to 30–60 ml hydrogen peroxide, and stirred at room temperature for 20–30 h. Then, the mixture was filtered to remove unreacted tungsten powder. The filtrate was heated at 60–100 °C for 20–60 min and allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 3–6% (v / v) of titanium source was added to the filtrate, and the mixture was allowed to stand for 12 h. Insoluble substances were then filtered out. The resulting Ti-doped WO3 precursor solution was then heated in an oil bath at 60–100 °C for 60–120 min with stirring. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 5–30% (v / v) of anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 4–8% (v / v) of PEDOT or PEDOT:PSS, and the mixture was shaken until homogeneous.

[0063] As another aspect of the technical solution of this invention, it also relates to a functional ink for WO3-based electrochromic photochromic glass prepared by the aforementioned preparation method. This functional ink has a simple composition and good stability, and is suitable for coating technology to prepare electrochromic films. The prepared films exhibit good electrochromic properties without the need for high-temperature annealing treatment.

[0064] Correspondingly, as another aspect of the technical solution of the present invention, it also relates to the application of the aforementioned functional ink for WO3-based electrochromic light-emitting glass in the preparation of WO3-based electrochromic light-emitting glass or WO3 electrochromic film.

[0065] Furthermore, another aspect of the present invention provides a method for preparing a WO3 electrochromic film, which includes applying the aforementioned functional ink for WO3-based electrochromic light-emitting glass onto a substrate through a coating process to form a WO3 electrochromic film.

[0066] Furthermore, the substrate can be any one of ITO / PET substrate, ITO / glass substrate, etc.

[0067] Specifically, the preparation method of the WO3 electrochromic film may include: combining a coating process to coat the aforementioned functional ink onto a substrate, depositing a Ti-doped WO3 electrochromic film, and then placing the film in a vacuum drying oven for vacuum drying.

[0068] Furthermore, another aspect of the present invention provides a WO3 electrochromic film prepared by the aforementioned preparation method.

[0069] Furthermore, the thickness of the WO3 electrochromic film is 250–400 nm.

[0070] In summary, based on the novel functional ink synthesized in this invention, combined with coating technology, a Ti-doped WO3-PEDOT inorganic-organic hybrid electrochromic film with an amorphous embedded nanocrystalline structure was prepared at low temperature, which can realize the large-size low-temperature preparation of WO3 electrochromic films.

[0071] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; all modifications conceived of or derived from the content disclosed herein are considered to be within the scope of protection of this invention.

[0072] Example 1

[0073] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 1g tungsten powder to 50ml hydrogen peroxide, and stirred at room temperature for 24 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 90℃ for 30 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 5% (v / v) tetrabutyl titanate was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered to remove the insoluble substances. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 100℃ for 90 minutes in an oil bath. After naturally cooling to room temperature, the functional ink was prepared. Specifically, 20% (v / v) anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 6.25% PEDOT. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0074] The prepared functional ink was coated onto an ITO / glass substrate using a coating process to deposit a Ti-doped WO3 electrochromic film (also known as a Ti-doped WO3-PEDOT film). The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0075] The inventors in this case also conducted the following tests on the obtained functional ink and Ti-doped WO3 electrochromic film:

[0076] Figure 1 The figure shows the particle size distribution of Ti-doped WO3 particles in the functional ink prepared in this embodiment. The figure indicates that the average particle size of the Ti-doped WO3 particles in the functional ink is 15 nm. Small particle size can shorten the ion transport distance of the deposited film, improve the uniformity and density of the film, and thus enhance the electrochromic performance.

[0077] Figure 2a , Figure 2b The images show surface and cross-sectional SEM images of the WO3 electrochromic film prepared using a coating technique based on functional inks. The SEM images reveal that the Ti-doped WO3-PEDOT film possesses a loose porous structure, which effectively reduces diffusion paths and promotes the insertion and extraction of electrolyte ions. Simultaneously, the film exhibits a uniform nanoparticle morphology, with nanoparticles of average size less than 20 nm distributed throughout the entire film, and a thickness of approximately 300 nm.

[0078] Figure 3a , Figure 3b AFM images (20.0 × 20.0 μm) of the surface of an ITO / glass substrate and the surface of a thin film based on an ITO / glass substrate, respectively. Figure 3a and Figure 3b The comparison revealed that the thin film and the ITO glass substrate had comparable root mean square roughness (Rq), indicating that the functional ink prepared in this embodiment has excellent film uniformity.

[0079] Figure 4a XRD patterns of ITO / glass-based thin films and ITO / glass-based films are shown. Figure 4a XRD results showed that the prepared film exhibited diffraction peaks other than those of ITO, indicating that WO3 has an amorphous structure. Furthermore, Figure 4b and Figure 4c The HRTEM image of the thin film shows clear stripes with interplanar spacings of 0.381 and 0.376 nm, corresponding to the interplanar spacings of the (002) and (020) crystal planes of monoclinic WO3 (PDF#43-1035), indicating that the Ti-doped WO3-PEDOT thin film has an amorphous embedded nanocrystal structure. The synergistic effect of the uniform distribution of nanocrystals in the amorphous matrix enables large light modulation, fast coloring and bleaching response speeds, and high coloring efficiency.

[0080] The high-resolution XPS spectra of W, Ti, and O are as follows: Figure 5a , Figure 5b and Figure 5c As shown. Figure 5a As shown in the XPS spectrum of W4f, W 6+ The peak values ​​are located at 35.8 and 37.9 eV, respectively. 5+ The peak values ​​are located at 34.6 and 36.8 eV, respectively. The XPS spectra of Ti 2p are as follows: Figure 5b As shown, the main peaks at 459.3 eV and 464.9 eV can be clearly observed, corresponding to Ti 2p3 / 2 and Ti2p1 / 2, confirming that Ti has been successfully doped into WO3. Figure 5c As shown, the O1s spectrum of WO3 has peaks centered at 530.6 eV, 531.9 eV, and 533.4 eV, corresponding to lattice oxygen, hydroxyl groups, and Ti hydroxide, respectively, indicating that Ti exists in the thin film as Ti... 4+ It exists in the form of hydroxides.

[0081] This invention also includes electrochromic performance tests on the thin films prepared above. All tests were conducted in a three-electrode system using 0.1M LiClO4@PC as the electrolyte, a Pt sheet as the counter electrode, and Ag / AgCl as the reference electrode. The coloring and fading spectra of the thin films in the wavelength range of 320–1000 nm are as follows: Figure 6a As shown, the transmittance curves of the thin film in the faded state (+1.0V) and colored state (-1.0V) are displayed. The optical modulation (ΔT) of the thin film at 633nm is 86.05% at ±1V. Figure 6b The in-situ transmittance spectrum of the thin film at a wavelength of 633 nm is shown in the voltage range of -1.0 V (20 s) to +1.0 V (20 s). The coloring time (t) of the thin film can be obtained from this spectrum. cThe contrast ratio (tb) is 10.4 s, and the fading time (tb) is 8.5 s. Fading time, as a kinetic indicator of the electrochemical reaction, is an important parameter for electrochromic applications. It is defined as the time required for an electrochromic material to achieve 90% full contrast when transitioning from one state to another. Figure 6c The graph shows the in-situ optical density of the thin film as a function of charge density, displaying the ratio of the optical density change (ΔOD) at 633 nm to the insertion charge of the oxide during the coloring process. The coloring efficiency (CE) is the slope of the fitted line in the linear region of the curve. The calculated CE of the thin film at 633 nm is as high as 54.1 cm⁻¹. 2 C -1 This indicates that a small amount of charge embedding per unit area can cause a large change in the optical density of the thin film. Figure 6d The image shows the results of a long-cycle test of 1000 cycles on the prepared thin film. It can be seen that the optical modulation retention rate of the thin film is 80.5% after 1000 cycles, indicating that the thin film has good cycling stability.

[0082] Example 2

[0083] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 1.8g tungsten powder to 60ml hydrogen peroxide, and stirred at room temperature for 24 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 100℃ for 50 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 3% (v / v) titanium tetraisopropoxide was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered to remove the insoluble substances. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 60℃ for 60 minutes in an oil bath. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 20% (v / v) anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 4% PEDOT. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0084] The prepared functional ink was coated onto an ITO / glass substrate using a coating process to deposit a Ti-doped WO3 electrochromic film (also known as a Ti-doped WO3-PEDOT film). The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0085] Example 3

[0086] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 0.6g tungsten powder to 30ml hydrogen peroxide, and stirred at room temperature for 20 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 60℃ for 20 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 6% (v / v) tetraisopropyl di(dioctylphosphite)titanate was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered out. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 100℃ for 100 minutes in an oil bath. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 5% (v / v) anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 8% PEDOT. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0087] The prepared functional ink was coated onto an ITO / glass substrate using a coating process to deposit a Ti-doped WO3 electrochromic film (also known as a Ti-doped WO3-PEDOT film). The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0088] Example 4

[0089] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 1.2g tungsten powder to 35ml hydrogen peroxide, and stirred at room temperature for 20 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 90℃ for 30 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 3% (v / v) tetrabutyl titanate was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered to remove the insoluble substances. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 90℃ for 60 minutes in an oil bath. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 30% (v / v) anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 5% PEDOT. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0090] The prepared functional ink was coated onto an ITO / PET substrate using a coating process to deposit a Ti-doped WO3 electrochromic film (also known as a Ti-doped WO3-PEDOT film). The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0091] Example 5

[0092] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 1.4g tungsten powder to 50ml hydrogen peroxide, and stirred at room temperature for 30 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 90℃ for 40 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 6% (v / v) titanium tetraisopropoxide was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered to remove the insoluble substances. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 70℃ for 70 minutes in an oil bath. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 26% (v / v) anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 7% PEDOT:PSS. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0093] The prepared functional ink was coated onto an ITO / PET substrate using a coating process to deposit a Ti-doped WO3 electrochromic film (also known as a Ti-doped WO3-PEDOT:PSS film). The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0094] Example 6

[0095] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 0.1g tungsten powder to 30ml hydrogen peroxide, and stirred at room temperature for 24 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 60℃ for 60 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 6% (v / v) titanium tetraisopropoxide was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered to remove the insoluble substances. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 60℃ for 120 minutes in an oil bath. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 30% (v / v) isopropanol was added to the Ti-doped WO3 precursor solution, followed by 6% PEDOT:PSS. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0096] The prepared functional ink was coated onto an ITO / PET substrate using a coating process to deposit a Ti-doped WO3 electrochromic film. The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0097] Example 7

[0098] First, tungsten powder and hydrogen peroxide (30%) were added to a beaker at a ratio of 2g tungsten powder to 60ml hydrogen peroxide, and stirred at room temperature for 30 hours. The mixture was then filtered to remove unreacted tungsten powder. The filtrate was heated at 90℃ for 40 minutes and then allowed to cool naturally to room temperature, yielding a clear, pale yellow solution. Next, 6% (v / v) titanium tetraisopropoxide was added, and the mixture was allowed to stand for 12 hours. Insoluble substances were then filtered to remove the insoluble substances. The resulting Ti-doped WO3 precursor solution was then heated and stirred at 80℃ for 70 minutes in an oil bath. After cooling naturally to room temperature, the functional ink was prepared. Specifically, 26% (v / v) anhydrous ethanol was added to the Ti-doped WO3 precursor solution, followed by 7% PEDOT:PSS. The mixture was shaken thoroughly to obtain the functional ink for WO3-based electrochromic color-changing glass.

[0099] The prepared functional ink was coated onto an ITO / PET substrate using a coating process to deposit a Ti-doped WO3 electrochromic film. The film was then placed in a vacuum drying oven and dried at 60°C for 1 hour.

[0100] Comparative Example 1

[0101] The difference between this comparative example and Example 1 is that 5% by volume of tetrabutyl titanate was not added.

[0102] The SEM results of the thin film obtained in this comparative example are as follows: Figure 7a As shown, the film surface is dense, and no pores were observed. The HRTEM image of this film is shown below. Figure 7b As shown, no lattice fringes are displayed, and no nanocrystals are present, indicating that the film has a completely amorphous structure. Figure 7c As shown, AFM testing revealed that the root mean square roughness of the film was 20.6 nm, indicating that the film surface was extremely rough. This suggests that the uniformity of the functional ink film formed without the addition of 5% tetrabutyl titanate was very poor.

[0103] The electrochromic properties of the prepared films were also tested under the following conditions: a three-electrode system using 0.1M LiClO4@PC as the electrolyte, a Pt sheet as the counter electrode, and Ag / AgCl as the reference electrode. The coloring and fading spectra of the films in the wavelength range of 320–1000 nm are as follows: Figure 7d As shown, the transmittance curves of the thin film in the faded state (+1.0V) and colored state (-1.0V) are displayed. The optical modulation (ΔT) of the thin film at 633nm is 43.94% at ±1V. Figure 7e The in-situ transmittance spectrum of the thin film at a wavelength of 633 nm is given under a voltage range of -1.0V (20s) to +1.0V (20s). The coloring time (tc) of the thin film is 3.7s and the fading time (tb) is 3.9s. Figure 7fThe graph shows the in-situ optical density of the thin film as a function of charge density, displaying the ratio of the optical density change (ΔOD) at 633 nm to the insertion charge of the oxide during the coloring process. The coloring efficiency (CE) is the slope of the fitted line in the linear region of the curve. The calculated CE of the thin film at 633 nm is 42.9 cm⁻¹. 2 C -1 The film is smaller than the film with 5% tetrabutyl titanate added by volume. Figure 7g The figure shows the test results of the prepared thin film after 20 cycles. It can be seen that the optical modulation retention rate of the thin film is only 73.9% after 20 cycles, indicating that the cycling stability of the thin film is extremely poor.

[0104] Comparative Example 2

[0105] The difference between this comparative example and Example 1 is that anhydrous ethanol was not added.

[0106] Because no anhydrous ethanol was added, the surface tension of the functional ink obtained in this comparative example was too high, and it could not be deposited on ITO / glass or ITO / PET substrates.

[0107] Comparative Example 3

[0108] The difference between this comparative example and Example 1 is that PEDOT was not added.

[0109] Because PEDOT was not added, the viscosity of the functional ink obtained in this comparative example was too low, resulting in extremely poor film uniformity on the ITO / glass or ITO / PET substrates. Furthermore, due to the absence of PEDOT, the prepared film did not exhibit electrochromic properties after low-temperature treatment at 60°C.

[0110] Comparative Example 4

[0111] The difference between this comparative example and Example 1 is that PEDOT is replaced with Triton X-100.

[0112] The film prepared in this comparative example did not exhibit electrochromic properties after low-temperature treatment at 60℃. The reason is that Triton X-100 is a nonionic surfactant that cannot be completely removed by low-temperature treatment. It will change the interfacial interaction between the film and the electrolyte, affecting the insertion and extraction process of ions, thereby causing the film to lose its electrochromic properties.

[0113] In addition, the inventors of this case also conducted experiments with other raw materials and conditions listed in this specification, referring to the aforementioned embodiments, and similarly obtained functional inks with good stability, moderate surface tension and viscosity, and good ink film-forming properties, as well as electrochromic films with good electrochromic properties.

[0114] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the described embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to include all embodiments falling within the defined scope.

Claims

1. A functional ink for WO3-based electrochromic tinting glass, characterized in that, The functional ink for WO3-based electrochromic light control glass comprises: Ti-doped WO3 particles and an auxiliary agent, the auxiliary agent comprising an alcohol and a conductive polymer, the conductive polymer comprising PEDOT:PSS and / or PEDOT.

2. The functional ink for WO3-based electrochromic tinting glass according to claim 1, characterized in that: The content of the Ti-doped WO3 particles in the functional ink is 5-20 wt%, the content of the alcohol is 10-20 wt%, and the content of the conductive polymer is 2-10 wt%. The alcohol comprises ethanol and / or isopropanol.

3. The functional ink for WO3-based electrochromic tinting glass according to claim 1, characterized in that: The particle size of the Ti-doped WO3 particles is 3-30 nm; the doping amount of Ti in the Ti-doped WO3 particles is 2-6 wt%; and the Ti-doped WO3 particles have an amorphous embedded nanocrystalline structure.

4. A method for the preparation of a functional ink for WO3-based electrochromic tinting glass, characterized in that, The method comprises: performing an oxidation reaction by fully contacting tungsten with hydrogen peroxide, and then adding a titanium source for doping treatment to obtain a Ti-doped WO3 precursor solution; heating the Ti-doped WO3 precursor solution, and then mixing the Ti-doped WO3 precursor solution with an alcohol and a conductive polymer to obtain a functional ink for WO3-based electrochromic light control glass, the conductive polymer comprising PEDOT:PSS and / or PEDOT.

5. The method of claim 4, wherein: The mass-volume ratio of the tungsten to the hydrogen peroxide is (0.1-2) g:(30-60) ml; and / or the temperature of the oxidation reaction is room temperature, and the time is 20-30 h. The method further comprises: after the oxidation reaction is completed, filtering, and heating the obtained filtrate at 60-100 ℃ for 20-60 min. The titanium source comprises any one or a combination of two or more of tetrabutyl titanate, titanium tetraisopropoxide, and tetraisopropyl di(dioctyl phosphityloxy) titanate; The volume fraction of the titanium source in the filtrate is 3-6%; The temperature for heating the Ti-doped WO3 precursor solution is 60-100 ℃, and the time is 60-120 min.

6. The method of claim 4, wherein: The alcohol comprises ethanol and / or isopropanol; The volume fraction of the alcohol in the Ti-doped WO3 precursor solution is 5-30%; The volume fraction of the conductive polymer in the Ti-doped WO3 precursor solution is 4-8%.

7. The functional ink for WO3-based electrochromic light control glass prepared by the method of any one of claims 4-6.

8. The use of the functional ink for WO3-based electrochromic light control glass of any one of claims 1-3 and 7 in the preparation of a WO3-based electrochromic light control glass or a WO3 electrochromic film.

9. A method for preparing a WO3 electrochromic thin film, characterized by, The method comprises: applying the functional ink for WO3-based electrochromic light control glass of any one of claims 1-3 and 7 to a substrate by a coating process to form a WO3 electrochromic film.

10. The WO3 electrochromic film prepared by the method of claim 9; preferably, the thickness of the WO3 electrochromic film is 250-400 nm.

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