Electrochromic device based on electro-deposition copper bismuth and hydrated tungsten oxide film and preparation method and application of electrochromic device

Abstract

The invention belongs to the technical field of materials, and provides an electrochromic device based on electrodeposited copper bismuth and a hydrated tungsten oxide film and a preparation method and application of the electrochromic device. The electrochromic device provided by the invention comprises a hydrated tungsten oxide device with a cavity and a copper-bismuth electrolyte arranged in the cavity of the hydrated tungsten oxide device, and by combining an electrochromic material and metal electrodeposition, the structure of a conventional device is changed; the light modulation amplitude of the device and the fitting degree of the electrolyte solution and the electrochromic device are improved, and the obtained device is good in cycling stability and high in response speed. Results of the embodiment show that the light modulation amplitude of the electrochromic device based on the electrodeposited copper bismuth and the hydrated tungsten oxide film can reach 78.3%, and 96.6% of the initial light modulation amplitude can still be kept after the electrochromic device is circulated for 60000s. In addition, the raw materials used in the invention are cheap and environment-friendly, conform to the idea of green chemistry, and have good industrial prospects.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and in particular to an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film, and a preparation method and application thereof. Background Art

[0002] As human environmental awareness increases, how to improve energy efficiency is the focus of today's society. It is reported that the heating, ventilation and air conditioning (HVAC) system in buildings alone accounts for 40% of the world's primary energy consumption. Smart windows can reduce energy consumption caused by lighting, heating and cooling by controlling light flux, saving 20% ​​of energy compared to fixed low-emissivity glass. Other studies have shown that the use of smart windows can relieve employee fatigue and increase productivity by 2%. Electrochromic technology is a technology that can improve energy efficiency and has a promising application in smart windows, with a more beautiful switching effect than traditional blinds.

[0003] Electrochromic materials or devices reversibly control their coloring and fading states by applying a bias voltage. Despite decades of research, traditional electrochromic devices have not been widely popularized in the market due to issues such as color, cost, speed, and durability. Reversible metal electrodeposition (RME) devices are a new type of electrochromic device with excellent spectral control capabilities in visible light, infrared and other bands, and have unique advantages such as simple structure, low energy consumption, and multi-color state control. They show great application potential in smart windows, thermal management, information display and other fields.

[0004] In 2020, Caroline Sunyong Lee et al. prepared a rough surface electrode by spraying WO3 nanoparticles on the surface of fluorine-doped tin oxide (FTO) electrode through a nanoparticle dry spraying system, and constructed a tri-state reversible Ag-based electrodeposition device (Son M, Shin D, Lee C S. Facile Fabrication of Trimodal Switchable Mirror Device with Zero Transmittance in the Black State. Advanced Materials Interfaces, 2021, 8 (3): 2001416.). Unlike traditional color-changing devices, RME devices do not have an electrochromic layer. The entire RME device operates under an external bias. Under the condition of applying a reduction voltage, metal ions are deposited on the working electrode (the device state changes from a faded state to a colored state); under the condition of an oxidation voltage, the metal dissolves and deposits on the counter electrode as the voltage increases (the device state changes from a colored state to a faded state). Due to the lack of electrochromic materials, metal electrodeposition-type electrochromic devices generally have disadvantages such as poor open-circuit stability and short cycle life. Summary of the invention

[0005] In view of this, the present invention provides an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film, and a preparation method and application thereof. The electrochromic device provided by the present invention combines the advantages of both electrochromic materials and metal electrodeposition, has good cycle stability, and the preparation method is simple. It can achieve different color change effects and transmittance adjustment of the device, and can be applied to smart glass, display and other fields.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] An electrochromic device based on electrodeposited copper-bismuth and hydrated tungsten oxide thin films, comprising a hydrated tungsten oxide device having a cavity and a copper-bismuth electrolyte disposed in the cavity of the hydrated tungsten oxide device;

[0008] The hydrated tungsten oxide device with a cavity is composed of a transparent conductive glass and a transparent conductive glass with a hydrated tungsten oxide film, and the hydrated tungsten oxide film is in contact with a copper-bismuth electrolyte;

[0009] The copper-bismuth electrolyte comprises a water-soluble copper salt, a water-soluble bismuth salt, a stabilizer and water;

[0010] The stabilizer includes water-soluble alkali metal salts and hydrogen chloride.

[0011] Preferably, the transparent conductive glass includes FTO glass or indium tin oxide (ITO) glass.

[0012] Preferably, the water-soluble copper salt is copper chloride; the water-soluble bismuth salt is bismuth chloride and / or bismuth nitrate; and the water-soluble alkali metal salt includes lithium chloride and / or potassium chloride.

[0013] Preferably, the molar ratio of the water-soluble copper salt to the water-soluble bismuth salt in the copper-bismuth electrolyte is 1:1 to 3.75:1.

[0014] Preferably, in the copper-bismuth electrolyte: the molar concentration of the water-soluble copper salt is 10-15 mmol / L, the molar concentration of the water-soluble bismuth salt is 4-10 mmol / L, the molar concentration of the water-soluble alkali metal salt is 0.8-1.5 mol / L, and the molar concentration of hydrogen chloride is 30-80 mmol / L.

[0015] Preferably, the distance between the surfaces of the transparent conductive glass and the transparent conductive glass with the hydrated tungsten oxide film respectively in contact with the copper-bismuth electrolyte is 0.8-1.1 mm.

[0016] The present invention provides a method for preparing an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to the above technical solution, comprising the following steps:

[0017] Placing transparent conductive glass in an electrodeposition solution for electrodeposition to obtain transparent conductive glass with a hydrated tungsten oxide film; the electrodeposition solution comprises sodium tungstate dihydrate, hydrogen peroxide, deionized water and nitric acid;

[0018] The transparent conductive glass with the hydrated tungsten oxide film and the transparent conductive glass are stacked and the edges are sealed to obtain a hydrated tungsten oxide device with a cavity;

[0019] The copper-bismuth electrolyte is injected into the cavity of the hydrated tungsten oxide device to obtain the electrochromic device based on the electrodeposited copper-bismuth and hydrated tungsten oxide film.

[0020] Preferably, the electrodeposition is carried out using a three-electrode system, wherein the working electrode is transparent conductive glass, the counter electrode is a platinum sheet, and the reference electrode is an Ag / AgCl electrode;

[0021] The electrodeposition is constant voltage electrodeposition; the voltage of the constant voltage electrodeposition is -0.5 to -0.8V;

[0022] The constant voltage electrodeposition time is 400 to 600 seconds.

[0023] Preferably, the molar ratio of sodium tungstate dihydrate to hydrogen peroxide is (2-10):(7-9), the molar concentration of sodium tungstate dihydrate in the electrodeposition solution is 10-50 mmol / L; and the pH value of the electrodeposition solution is 1-2.

[0024] The present invention provides an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film as described in the above technical scheme, or an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by the preparation method described in the above technical scheme, and its application in smart windows.

[0025] The present invention provides an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide film, comprising a hydrated tungsten oxide device with a cavity and a copper bismuth electrolyte arranged in the cavity of the hydrated tungsten oxide device; the hydrated tungsten oxide device with a cavity is composed of transparent conductive glass and transparent conductive glass with a hydrated tungsten oxide film; the hydrated tungsten oxide film is in contact with the copper bismuth electrolyte; the copper bismuth electrolyte comprises a water-soluble copper salt, a water-soluble bismuth salt, a stabilizer and water; the stabilizer comprises a water-soluble alkali metal salt and hydrogen chloride. The present invention changes the structure of the previous device by combining electrochromic materials and metal electrodeposition, using transparent conductive glass as a counter electrode, and using a transparent conductive glass with a hydrated tungsten oxide film on one surface as a working electrode, and cooperating with the copper bismuth electrolyte to improve the light modulation amplitude of the device and the fit between the electrolyte solution and the electrochromic device (that is, the device provided by the present invention has excellent electrochromic performance). The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide film described in the present invention has good cycle stability and a faster response speed. The examples show that the light modulation amplitude of the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film of the present invention can reach 78.3%, and it can still maintain 96.6% of the initial light modulation amplitude after 60,000 seconds of circulation. In addition, the hydrated tungsten oxide device with a cavity of the present invention is filled with an electrolyte instead of a gel with a relatively complex preparation method. The raw materials used in the technical solution of the present invention are cheap and easy to obtain, have low requirements on the experimental environment, are harmless to the human body, and have good industrial prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Effect diagrams of the electrochromic device in the faded state (a) and colored state (b) using the electrodeposited hydrated tungsten oxide thin film prepared in Example 1 of the present invention and based on the electrodeposited copper bismuth and hydrated tungsten oxide thin film;

[0027] Figure 2 Scanning electron microscope photo of the hydrated tungsten oxide film prepared by Example 1 of the present invention;

[0028] Figure 3 Cyclic voltammetry curve of an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by Example 1 of the present invention;

[0029] Figure 4 Response time curve of the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by Example 1 of the present invention;

[0030] Figure 5 The transmittance curve of the electrochromic device based on the electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by Example 1 of the present invention;

[0031] Figure 6Cyclic stability curve of the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The present invention provides an electrochromic device based on electrodeposited copper-bismuth and hydrated tungsten oxide thin films, comprising a hydrated tungsten oxide device having a cavity and a copper-bismuth electrolyte disposed in the cavity of the hydrated tungsten oxide device;

[0033] The hydrated tungsten oxide device with a cavity is composed of a transparent conductive glass and a transparent conductive glass with a hydrated tungsten oxide film, and the hydrated tungsten oxide film is in contact with a copper-bismuth electrolyte;

[0034] The copper-bismuth electrolyte comprises a water-soluble copper salt, a water-soluble bismuth salt, a stabilizer and water;

[0035] The stabilizer includes water-soluble alkali metal salts and hydrogen chloride.

[0036] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0037] The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film provided by the present invention includes a hydrated tungsten oxide device with a cavity. In the present invention, the hydrated tungsten oxide device with a cavity is composed of transparent conductive glass and transparent conductive glass with a hydrated tungsten oxide thin film, and the hydrated tungsten oxide thin film is in contact with a copper bismuth electrolyte.

[0038] In the present invention, the transparent conductive glass is used as the counter electrode of the electrochromic device based on the electrodeposited copper bismuth and hydrated tungsten oxide thin film. The transparent conductive glass preferably includes FTO glass or ITO glass.

[0039] In the present invention, the transparent conductive glass with hydrated tungsten oxide thin film is used as the working electrode of the electrochromic device based on electrodeposition of copper bismuth and hydrated tungsten oxide thin film. The transparent conductive glass with hydrated tungsten oxide thin film preferably includes FTO glass with hydrated tungsten oxide thin film on one surface or ITO glass with hydrated tungsten oxide thin film on one surface.

[0040] In the present invention, the distance between the surfaces of the transparent conductive glass and the transparent conductive glass with hydrated tungsten oxide film respectively in contact with the copper-bismuth electrolyte is preferably 0.8-1.1 mm.

[0041] In the present invention, the transparent conductive glass and the transparent conductive glass with hydrated tungsten oxide film preferably form a cavity structure through a connector, which is preferably one or more of double-sided adhesive, glass adhesive, adhesive tape or glue.

[0042] The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film provided by the present invention comprises a copper bismuth electrolyte disposed in the cavity of the hydrated tungsten oxide device. In the present invention, the copper bismuth electrolyte comprises a water-soluble copper salt, a water-soluble bismuth salt, a stabilizer and water; the stabilizer comprises a water-soluble alkali metal salt and hydrogen chloride.

[0043] In the present invention, the water-soluble copper salt is preferably copper chloride, and more preferably copper chloride dihydrate; the water-soluble bismuth salt is preferably bismuth chloride and / or bismuth nitrate; the water-soluble alkali metal salt preferably includes lithium chloride and / or potassium chloride. In a specific embodiment of the present invention, the stabilizer is preferably lithium chloride and hydrogen chloride. Alternatively, the stabilizer is preferably potassium chloride and hydrogen chloride.

[0044] The water-soluble alkali metal salt and the water-soluble bismuth salt can form a complex to inhibit the hydrolysis of the water-soluble bismuth salt, thereby playing a stabilizing role.

[0045] In the present invention, the water is preferably deionized water. In a preferred embodiment of the present invention, the deionized water does not contain Cl-, SO4 2- 、NO3 - 、NO2 - PO4 3- 、HPO4 2- Mg 2+ , Ca 2+ , Fe 3+ and Fe 2+ Water containing any ion.

[0046] In the present invention, the copper-bismuth electrolyte preferably includes copper chloride, bismuth chloride, potassium chloride, hydrogen chloride and deionized water, or the copper-bismuth electrolyte preferably includes copper chloride, bismuth chloride, lithium chloride, hydrogen chloride and deionized water.

[0047] In the present invention, the method for preparing the copper-bismuth electrolyte is preferably: mixing the water-soluble copper salt, the water-soluble bismuth salt, the water-soluble alkali metal salt, hydrochloric acid and water to obtain the copper-bismuth electrolyte.

[0048] In the present invention, the molar ratio of the water-soluble copper salt to the water-soluble bismuth salt in the copper-bismuth electrolyte is 1:1 to 3.75:1, more preferably 1:3 to 3:1.

[0049] In the present invention, when the copper-bismuth electrolyte preferably includes copper chloride, bismuth chloride, potassium chloride, hydrogen chloride and deionized water, the concentration of each component in the copper-bismuth electrolyte is preferably: copper chloride 10-15 mmol / L, bismuth chloride or bismuth nitrate 4-10 mmol / L, potassium chloride 0.8-1.5 mol / L and hydrogen chloride 30-80 mmol / L; more preferably copper chloride 11-14 mmol / L, bismuth chloride or bismuth nitrate 5-8 mmol / L, potassium chloride 1-1.3 mol / L and hydrogen chloride 35-70 mmol / L.

[0050] In the present invention, when the copper-bismuth electrolyte comprises copper chloride, bismuth chloride, lithium chloride, hydrogen chloride and deionized water, the concentration of each component in the copper-bismuth electrolyte is preferably: copper chloride 10-15 mmol / L, bismuth chloride or bismuth nitrate 4-10 mmol / L, lithium chloride 0.8-1.5 mol / L and hydrogen chloride 30-80 mmol / L; more preferably copper chloride 11-14 mmol / L, bismuth chloride or bismuth nitrate 5-8 mmol / L, lithium chloride 1-1.3 mol / L and hydrogen chloride 35-70 mmol / L.

[0051] In a specific embodiment of the present invention, the different color changing effects and transmittance adjustment of the electrochromic device are preferably achieved through electric field control.

[0052] The present invention also provides a method for preparing an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film as described in the above scheme, comprising the following steps:

[0053] Placing transparent conductive glass in an electrodeposition solution for electrodeposition to obtain transparent conductive glass with a hydrated tungsten oxide film; the electrodeposition solution comprises sodium tungstate dihydrate, hydrogen peroxide, deionized water and nitric acid;

[0054] The transparent conductive glass with the hydrated tungsten oxide film and the transparent conductive glass are stacked and the edges are sealed to obtain a hydrated tungsten oxide device with a cavity;

[0055] The copper-bismuth electrolyte is injected into the cavity of the hydrated tungsten oxide device to obtain the electrochromic device based on the electrodeposited copper-bismuth and hydrated tungsten oxide film.

[0056] The present invention places transparent conductive glass in an electrodeposition solution for electrodeposition to obtain transparent conductive glass with a hydrated tungsten oxide film; the components of the electrodeposition solution include sodium tungstate dihydrate, hydrogen peroxide, deionized water and nitric acid. In the present invention, the electrodeposition is preferably carried out using a three-electrode system, the working electrode is preferably transparent conductive glass, specifically preferably FTO glass or ITO glass, the counter electrode is preferably a platinum sheet, and the reference electrode is preferably an Ag / AgCl electrode; the electrodeposition is preferably constant voltage electrodeposition; the voltage of the constant voltage electrodeposition is -0.5 to -0.8V, specifically -0.7V in the embodiment; the time of the constant voltage electrodeposition is preferably 400 to 600s.

[0057] In the present invention, the molar ratio of sodium tungstate dihydrate to hydrogen peroxide is preferably (2-10): (7-9), and in the embodiments, it is specifically 10:8, 5:9 or 2:7. The molar concentration of sodium tungstate dihydrate in the electrodeposition solution is preferably 10-50 mmol / L, and in the embodiments, it is specifically 10 mmol / L, 25 mmol / L or 50 mmol / L. The pH value of the electrodeposition solution is preferably 1-2. In a specific embodiment of the present invention, it is preferred to first mix sodium tungstate dihydrate, hydrogen peroxide and deionized water, and then add nitric acid to adjust the pH of the mixed solution to 1-2, so as to obtain the electrodeposition solution.

[0058] After obtaining the transparent conductive glass with the hydrated tungsten oxide film, the present invention stacks the transparent conductive glass with the hydrated tungsten oxide film and the transparent conductive glass, and seals the edges to obtain a hydrated tungsten oxide device with a cavity. In the present invention, when stacking, it is preferred that the side of the transparent conductive glass with the hydrated tungsten oxide film deposited with the hydrated tungsten oxide film faces the cavity, and is in direct contact with the copper-bismuth electrolyte; the type of the connecting object and the thickness of the cavity are not repeated here.

[0059] After obtaining the hydrated tungsten oxide device with a cavity, the present invention injects a copper-bismuth electrolyte into the cavity of the hydrated tungsten oxide device to obtain the electrochromic device based on the electrodeposited copper-bismuth and hydrated tungsten oxide thin film. The present invention has no special requirements for the injection method, and a method familiar to those skilled in the art can be used.

[0060] The present invention also provides the application of the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film described in the above technical scheme or the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by the preparation method described in the above technical scheme in smart windows.

[0061] In the present invention, the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film preferably has a coloring voltage of -3V and a coloring time of 15 to 30s; the fading voltage is preferably 1 to 1.5V, and the fading time is preferably 16 to 30s.

[0062] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Example 1

[0064] (1) 0.25 g of cupric chloride dihydrate, 0.15 g of bismuth chloride, 2.11 g of lithium chloride, and 0.36 mL of 36% hydrochloric acid were mixed and dissolved with deionized water to obtain 100 mL of liquid electrolyte (i.e., copper-bismuth electrolyte).

[0065] (2) Preparation of hydrated tungsten oxide thin film by electrodeposition: In a three-electrode system, 10 mmol of sodium tungstate dihydrate, 8 mmol of hydrogen peroxide and deionized water were mixed and an appropriate amount of nitric acid was added to adjust the pH of the mixed solution to 1 to obtain 200 mL of electrodeposition solution. The transparent conductive substrate FTO glass was used as the working electrode, the platinum sheet was used as the counter electrode, and the Ag / AgCl electrode was used as the reference electrode. The hydrated tungsten oxide thin film was prepared by -0.7 V, 400 s constant voltage electrodeposition method, that is, FTO glass with a hydrated tungsten oxide thin film was obtained; the FTO glass with a hydrated tungsten oxide thin film and a piece of FTO glass were bonded together with a 1 mm thick transparent double-sided tape to obtain a hydrated tungsten oxide device with a cavity.

[0066] (3) Injecting the copper-bismuth electrolyte prepared in step (1) into the cavity of a hydrated tungsten oxide device having a cavity, thereby obtaining an electrochromic device based on electrodeposited copper-bismuth and hydrated tungsten oxide thin films.

[0067] Figure 1 The fading state of the electrochromic device based on the electrodeposited hydrated tungsten oxide film prepared by Example 1 of the present invention and the electrodeposited copper bismuth and hydrated tungsten oxide film is as follows: Figure 1 The effect diagram shown in (a) in the figure; the colored state is as follows Figure 1 The effect diagram (b) is shown in FIG. The coloring voltage is -3V, the time is 30s, and the fading voltage is 1V, the time is 30s.

[0068] The scanning electron microscope photo of the hydrated tungsten oxide film prepared in this example is shown in FIG. Figure 2 As shown. Figure 2 It can be seen that in this embodiment, the free movement of ions is relatively easy, and it is suitable for fields such as electrochromic electrolytes.

[0069] The scanning cyclic voltammetry (CV) curve of the electrochromic device based on the electrodeposited copper bismuth and hydrated tungsten oxide thin film obtained in this embodiment is as follows: Figure 3As shown, -3 V was selected as the coloring voltage, 1 V was selected as the fading voltage, the electrochemical workstation was used in conjunction with a UV-Vis-NIR spectrophotometer, and the test was carried out in the wavelength range of 400 to 1100 nm. The transmittance reached a maximum at a wavelength of 570 nm, and the light modulation amplitude of the electrochromic device transitioned between -3 V and 1 V every 30 seconds to form a light response curve. All data were measured at 570 nm.

[0070] Figure 4 The response time curve of the electrochromic device based on the electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by Example 1 of the present invention is shown, wherein the response time is the time required for the electrochromic device to achieve 90% of the maximum light modulation amplitude. The device quickly turns blue-black at a voltage of -3V, and when a voltage of 1.5V is applied, the device changes from blue-black to colorless. It is calculated that when the light modulation amplitude change value reaches 90%, the coloring time of the electrochromic device based on the electrodeposited copper bismuth and hydrated tungsten oxide thin film is about 15.8s, and the fading time is about 16.2s. Figure 5 This is the transmittance curve of the copper bismuth and hydrated tungsten oxide film based on electrodeposition prepared by Example 1 of the present invention. The transmittance change at 570 nm between the colored state and the faded state is the largest, which is about 78.3%. Figure 6 This is a cycle stability curve of the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared in Example 1 of the present invention, and after cycling for 60,000 seconds, 96.6% of the initial light modulation amplitude can still be maintained.

[0071] Example 2

[0072] (1) 0.25 g of cupric chloride dihydrate, 0.24 g of bismuth nitrate, 2.11 g of lithium chloride, 0.50 mL of 36% hydrochloric acid and deionized water were mixed and dissolved to obtain 100 mL of liquid electrolyte.

[0073] (2) Preparation of hydrated tungsten oxide thin film by electrodeposition: In a three-electrode system, 5 mmol of sodium tungstate dihydrate, 9 mmol of hydrogen peroxide and 2% deionized water were mixed and an appropriate amount of nitric acid was added to adjust the pH of the mixed solution to 1 to obtain 200 mL of electrodeposition solution. The transparent conductive substrate FTO glass was used as the working electrode, the platinum sheet was used as the counter electrode, and the Ag / AgCl electrode was used as the reference electrode. The hydrated tungsten oxide thin film was prepared by -0.7 V, 400 s constant voltage electrodeposition method, that is, FTO glass with a hydrated tungsten oxide thin film was obtained; the FTO glass with a hydrated tungsten oxide thin film and a piece of FTO glass were bonded together with a 1 mm thick transparent double-sided tape to obtain a hydrated tungsten oxide device with a cavity.

[0074] (3) Injecting an electrolyte into the cavity of the hydrated tungsten oxide device having a cavity, thereby obtaining an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film.

[0075] Example 3

[0076] (1) 0.25 g of cupric chloride dihydrate, 0.24 g of bismuth nitrate, 7.45 g of potassium chloride, and 0.45 mL of 36% hydrochloric acid were mixed and dissolved with deionized water to obtain 100 mL of liquid electrolyte.

[0077] (2) Preparation of hydrated tungsten oxide thin film by electrodeposition: In a three-electrode system, 2 mmol of sodium tungstate dihydrate, 7 mmol of hydrogen peroxide and deionized water were mixed and an appropriate amount of nitric acid was added to adjust the pH of the mixed solution to 1 to obtain 200 mL of electrodeposition solution. A platinum sheet was used as a counter electrode and an Ag / AgCl electrode was used as a reference electrode. A hydrated tungsten oxide thin film was prepared by a -0.7 V, 400 s constant voltage electrodeposition method to obtain an FTO glass with a hydrated tungsten oxide thin film. The FTO glass with a hydrated tungsten oxide thin film and a piece of FTO glass were bonded together with a 1 mm thick transparent double-sided tape to obtain a hydrated tungsten oxide device with a cavity.

[0078] (3) Injecting an electrolyte into the cavity of a hydrated tungsten oxide device having a cavity, thereby obtaining an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film.

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film, characterized in that: It comprises a hydrated tungsten oxide device having a cavity and a copper-bismuth electrolyte disposed in the cavity of the hydrated tungsten oxide device; The hydrated tungsten oxide device with a cavity is composed of transparent conductive glass and transparent conductive glass with a hydrated tungsten oxide film; the hydrated tungsten oxide film is in contact with a copper-bismuth electrolyte; The copper-bismuth electrolyte comprises a water-soluble copper salt, a water-soluble bismuth salt, a stabilizer and water; The stabilizer includes water-soluble alkali metal salts and hydrogen chloride.

2. The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to claim 1, characterized in that: The transparent conductive glass includes fluorine-doped tin oxide glass or indium tin oxide glass.

3. The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to claim 1, characterized in that: The water-soluble copper salt is copper chloride; the water-soluble bismuth salt is bismuth chloride and / or bismuth nitrate; the water-soluble alkali metal salt includes lithium chloride and / or potassium chloride.

4. The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to claim 1 or 3, characterized in that: The molar ratio of the water-soluble copper salt to the water-soluble bismuth salt in the copper-bismuth electrolyte is 1:1 to 3.75:

1.

5. The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to claim 1 or 3, characterized in that: In the copper-bismuth electrolyte, the molar concentration of the water-soluble copper salt is 10-15 mmol / L, the molar concentration of the water-soluble bismuth salt is 4-10 mmol / L, the molar concentration of the water-soluble alkali metal salt is 0.8-1.5 mol / L, and the molar concentration of hydrogen chloride is 30-80 mmol / L.

6. The electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to claim 1 or 2, characterized in that: The distance between the surfaces of the transparent conductive glass and the transparent conductive glass with the hydrated tungsten oxide film respectively contacting with the copper-bismuth electrolyte is 0.8-1.1 mm.

7. The method for preparing an electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film according to any one of claims 1 to 6, characterized in that: The following steps are involved: Placing transparent conductive glass in an electrodeposition solution for electrodeposition to obtain transparent conductive glass with a hydrated tungsten oxide film; the electrodeposition solution comprises sodium tungstate dihydrate, hydrogen peroxide, deionized water and nitric acid; The transparent conductive glass with the hydrated tungsten oxide film and the transparent conductive glass are stacked and the edges are sealed to obtain a hydrated tungsten oxide device with a cavity; The copper-bismuth electrolyte is injected into the cavity of the hydrated tungsten oxide device to obtain the electrochromic device based on the electrodeposited copper-bismuth and hydrated tungsten oxide film.

8. The preparation method according to claim 7, characterized in that: The electrodeposition is carried out using a three-electrode system, wherein the working electrode is transparent conductive glass, the counter electrode is a platinum sheet, and the reference electrode is an Ag / AgCl electrode; The electrodeposition is constant voltage electrodeposition; the voltage of the constant voltage electrodeposition is -0.5 to -0.8V; The constant voltage electrodeposition time is 400 to 600 seconds.

9. The preparation method according to claim 7, characterized in that: The molar ratio of sodium tungstate dihydrate to hydrogen peroxide is (2-10):(7-9), the molar concentration of sodium tungstate dihydrate in the electrodeposition solution is 10-50 mmol / L; and the pH value of the electrodeposition solution is 1-2.

10. Use of the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film as described in any one of claims 1 to 6 or the electrochromic device based on electrodeposited copper bismuth and hydrated tungsten oxide thin film prepared by the preparation method described in any one of claims 7 to 9 in smart windows.

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