Electrochromic material based on metal electrodeposition principle, preparation method and application of electrochromic material and electrochromic device

Abstract

The invention provides an electrochromic material based on a metal electrodeposition principle, a preparation method and application of the electrochromic material and an electrochromic device, and belongs to the technical field of electrochromic materials. The preparation method comprises the following steps: mixing soluble metal salt, electrolyte and water to obtain a metal electrodeposition aqueous solution, and pouring the metal electrodeposition aqueous solution into hydrogel to obtain the electrochromic material. According to the non-liquid metal electrodeposition electrochromic system provided by the invention, hydrogel is combined with a metal electrodeposition aqueous solution, and the metal electrodeposition aqueous solution with a reversible metal electrodeposition function is combined with the hydrogel and adsorbed into a network skeleton of the hydrogel by utilizing the swelling adsorption effect of the hydrogel, so that the metal electrodeposition electrochromic system is obtained. The hydrogel with a metal electrodeposition function is prepared by using a metal electrodeposition technology, the hydrogel is endowed with an electrochromic characteristic, the safety and transportable characteristic of the hydrogel are improved, the application value of an electrochromic material is improved, and the problem that an existing metal electrodeposition electrochromic material system usually exists in a liquid state during application and is difficult to apply is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochromic materials, and in particular to an electrochromic material based on the principle of metal electrodeposition, a preparation method and application thereof, and an electrochromic device. Background Art

[0002] Electrochromic materials and devices based on the principle of metal electrodeposition have attracted much attention in recent years due to their great application value in the fields of panoramic dimming skylights for new energy vehicles, intelligent windows for building light and heat regulation, and non-luminous electronic displays. The principle of electrochromism is generally that a specific material undergoes oxidation and reduction under the action of an electric field, inducing changes in its own chemical structure. Materials with different structures have differentiated optical properties (color, transmittance, reflectivity, absorptivity, etc.), thus exhibiting electric field-driven reversible optical switching properties. Currently, the most widely used electrochromic materials, such as inorganic tungsten oxides, organic small molecule viologens, and organic conductive polymer polythiophene materials, are mostly based on the redox regulation of materials to achieve the regulation of their optical properties. They generally require complex structural design and a long synthesis process, and have high R&D costs. At the same time, traditional material systems face problems such as difficulty in achieving black, limited spectral regulation, and limited optical modulation.

[0003] In recent years, electrochromic systems based on the principle of reversible metal electrodeposition have received widespread attention. The electrochromic principle of this type of system is: the deposition and dissolution of metal films are regulated by electric fields, and the optical transmittance difference between metal films and metal ion solutions is used to achieve reversible regulation of optical properties by electric fields. Its raw materials are easily available, no synthesis is required, and it has a low cost. At the same time, due to the special optical properties of metal films, it exhibits specific intelligent color-changing characteristics of neutral colors, which is of great value in new electrochromic application fields.

[0004] However, most of the current electrodeposition systems are liquid, such as the silver ion-dimethyl sulfoxide combination system, the copper ion-aqueous solution combination system, etc. Although metal ions have good fluidity and ionic conductivity under liquid conditions, liquid materials have a safety risk of leakage after device preparation. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an electrochromic material based on the principle of metal electrodeposition, a preparation method and application thereof, and an electrochromic device. The electrochromic material of the present invention imparts electrochromic properties to hydrogels, solving the problem that the existing metal electrodeposition electrochromic material system exists in liquid form when used and is difficult to use.

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

[0007] The present invention provides a method for preparing an electrochromic material based on the principle of metal electrodeposition, comprising the following steps:

[0008] mixing a soluble metal salt, an electrolyte and water to obtain a metal electrodeposition aqueous solution;

[0009] The metal electrodeposition aqueous solution is poured into the hydrogel to obtain the electrochromic material.

[0010] Preferably, the metal ions in the soluble metal salt include one or more of copper ions, zinc ions, bismuth ions and silver ions.

[0011] Preferably, the hydrogel comprises one or more of polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyacrylic acid (PAA), polyacrylamide (PAAM), polyethylene oxide (PEO) and polyhydroxyethyl methacrylate (PHEMA).

[0012] Preferably, the concentration of metal ions in the metal electrodeposition aqueous solution is 1 to 100 g / L.

[0013] Preferably, the volume ratio of the metal electrodeposition aqueous solution to the hydrogel is 1:1-3.

[0014] Preferably, the electrolyte comprises one or more of a lithium salt, a sodium salt and a potassium salt.

[0015] Preferably, the mixing further comprises adding an inorganic acid.

[0016] The present invention also provides an electrochromic material based on the metal electrodeposition principle obtained by the preparation method described in the above technical solution.

[0017] The present invention also provides the application of the electrochromic material based on the metal electrodeposition principle described in the above technical solution in anti-glare rearview mirrors, building curtain walls, automobile skylights, electronic tags and electronic billboards.

[0018] The present invention also provides an electrochromic device, comprising a first conductive electrode, the electrochromic material described in the above technical solution, and a second conductive electrode which are stacked in sequence.

[0019] The invention provides a method for preparing an electrochromic material based on the metal electrodeposition principle, comprising the following steps: mixing a soluble metal salt, an electrolyte and water to obtain a metal electrodeposition aqueous solution; and pouring the metal electrodeposition aqueous solution into a hydrogel to obtain the electrochromic material.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a non-liquid metal electrodeposition electrochromic system, by combining a hydrogel with a metal electrodeposition aqueous solution, utilizing the swelling and adsorption effect of the hydrogel, combining the metal electrodeposition aqueous solution with a reversible metal electrodeposition function with the hydrogel, and adsorbing it into the network skeleton of the hydrogel, preparing a hydrogel with a metal electrodeposition function, thereby realizing the development of a new type of electrochromic material, giving the hydrogel electrochromic properties, improving its safety and transportability, and improving the application value of the electrochromic material, solving the problem that the existing metal electrodeposition electrochromic material system usually exists in a liquid form when applied and is difficult to apply. In addition, the preparation method of the present invention is easy to implement, low in cost, can achieve reversible regulation of the reflectivity of optical properties, and at the same time has low cost and is green and environmentally friendly, avoiding the use of organic solvents, and is expected to promote the promotion and application of metal electrodeposition electrochromic material systems.

[0022] The present invention also provides an electrochromic material based on the metal electrodeposition principle obtained by the preparation method described in the above technical solution, which can control the reversible switching of optical transmittance by voltage in a non-liquid state to achieve efficient regulation of optical properties. In addition, the electrochromic material of the present invention can achieve stable neutral color (colorless-black) switching, which is conducive to promoting the large-scale application of electrochromic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the electrochromic device of the present invention;

[0024] Figure 2 This is a physical picture of the electrochromic material based on the metal electrodeposition principle prepared in Example 1;

[0025] Figure 3 This is a schematic structural diagram of the electrochromic device of Example 1;

[0026] Figure 4 The transmittance spectra of the electrochromic device of Example 1 at different voltages;

[0027] Figure 5 These are photos of the electrochromic device of Example 1 in a colorless state and a colored state;

[0028] Figure 6 This is a physical picture of the electrochromic material based on the metal electrodeposition principle prepared in Example 2;

[0029] Figure 7 The transmittance spectra of the electrochromic device of Example 2 at different voltages;

[0030] Figure 8 These are photos of the electrochromic device of Example 3 in a colorless state and a colored state;

[0031] Fig. 9The transmittance spectra of the electrochromic device of Example 3 at different voltages;

[0032] Fig.10 is the transmittance spectrum of the comparative electrochromic device at different voltages;

[0033] Fig.11 These are photos of the comparative electrochromic device in the colorless state and the colored state. DETAILED DESCRIPTION

[0034] The present invention provides a method for preparing an electrochromic material based on the principle of metal electrodeposition, comprising the following steps:

[0035] mixing a soluble metal salt, an electrolyte and water to obtain a metal electrodeposition aqueous solution;

[0036] The metal electrodeposition aqueous solution is poured into the hydrogel to obtain the electrochromic material.

[0037] In the present invention, unless otherwise specified, the raw materials used are all commercially available products in the art.

[0038] The invention mixes soluble metal salt, electrolyte and water to obtain metal electrodeposition aqueous solution.

[0039] In the present invention, the metal ions in the soluble metal salt preferably include one or more of copper ions, zinc ions, bismuth ions and silver ions, and more preferably include copper ions and bismuth ions.

[0040] The present invention has no particular limitation on the specific type of the soluble metal salt, and raw materials familiar to those skilled in the art may be used.

[0041] In the present invention, the electrolyte preferably includes one or more of lithium salts, sodium salts and potassium salts, the lithium salt more preferably includes one or more of lithium perchlorate, lithium bromide and lithium chloride, the sodium salt is more preferably sodium chloride, and the potassium salt is more preferably potassium chloride. The function of the electrolyte is to improve the ionic conductivity of the aqueous solution and promote the improvement of the optical switching performance of the system.

[0042] In the present invention, the mass ratio of the soluble metal salt to the electrolyte is preferably 6-18:50-100, specifically 6:50-100, 8:50-100, 11:50-100, 13:50-100, 15:50-100 or 18:50-100.

[0043] In the present invention, the mixing preferably further comprises adding an inorganic acid.

[0044] In the present invention, the inorganic acid is preferably a hydrochloric acid solution, the concentration of the hydrochloric acid solution is preferably 1.2 mol / L, the dosage ratio of the soluble metal salt to the hydrochloric acid solution is preferably 6-18 mg:2-10 mL, specifically 6 mg:4 mL, 8 mg:4 mL, 11 mg:4 mL, 13 mg:4 mL, 15 mg:4 mL or 18 mg:4 mL; the function of the hydrochloric acid solution is to increase the solubility of metal ions (such as bismuth ions) and prevent the hydrolysis of metal ions to produce insoluble substances (such as bismuth hydroxide).

[0045] In the present invention, the preferred concentration of metal ions in the metal electrodeposition aqueous solution is 1 to 100 g / L, specifically 1, 6, 15, 18, 20, 50, 80 or 100 g / L.

[0046] After obtaining the metal electrodeposition aqueous solution, the present invention pours the metal electrodeposition aqueous solution into the hydrogel to obtain the electrochromic material.

[0047] In the present invention, the hydrogel preferably includes one or more of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, polyethylene oxide and polyhydroxyethyl methacrylate.

[0048] In a specific embodiment of the present invention, the preparation method of the polyacrylamide is as follows:

[0049] Acrylamide monomer, initiator, cross-linking agent, catalyst and water are mixed to obtain a precursor solution, and the precursor solution is degassed and then subjected to polymerization reaction to obtain the polyacrylamide.

[0050] In the present invention, the amount of the acrylamide monomer is preferably 5% to 10% of the mass of water, the amount of the initiator is preferably 0.1% to 1.0% of the mass of water, the amount of the cross-linking agent is preferably 0.05% to 2.0% of the mass of water, and the amount of the catalyst is preferably 0.1% to 2.0% of the mass of water.

[0051] In the present invention, the initiator is preferably a photoinitiator or a thermal initiator, more preferably one or more of potassium persulfate, ammonium persulfate, cerium ammonium nitrate, Irgacure 2959 (hydrophilic photoinitiator) and Irgacure 651 (hydrophobic photoinitiator); the crosslinking agent is preferably N,N'-methylenebisacrylamide, an epoxy compound or a multifunctional monomer; the catalyst is preferably N,N,N',N'-tetramethylethylenediamine.

[0052] In the present invention, the degassing treatment is preferably carried out in a vacuum chamber, and the obtained solution is sealed and then put into an oven for baking at 60° C. for 12 hours to obtain the polyacrylamide.

[0053] In the present invention, the volume ratio of the metal electrodeposition aqueous solution to the hydrogel is preferably 1:1-3, specifically 1:1, 1:2 or 1:3. By controlling the volume ratio of the metal electrodeposition aqueous solution to the hydrogel, the proportion of the metal electrodeposition aqueous solution in the overall electrochromic hydrogel can be controlled, thereby regulating the electrochromic properties of the hydrogel.

[0054] In the present invention, the metal electrodeposition aqueous solution and the hydrogel are preferably placed in the same container, sealed and allowed to stand for 12 hours to obtain the electrochromic material. During the standing process, the metal electrodeposition aqueous solution is adsorbed into the skeleton network structure of the hydrogel by utilizing the swelling effect of the hydrogel.

[0055] The present invention also provides an electrochromic material based on the metal electrodeposition principle obtained by the preparation method described in the above technical solution.

[0056] The present invention also provides the application of the electrochromic material based on the metal electrodeposition principle described in the above technical solution in anti-glare rearview mirrors, building curtain walls, automobile skylights, electronic tags and electronic billboards.

[0057] The present invention also provides an electrochromic device, comprising a first conductive electrode, the electrochromic material described in the above technical solution, and a second conductive electrode which are stacked in sequence.

[0058] Figure 1 Schematic diagram of the structure of the electrochromic device.

[0059] In the present invention, the first conductive electrode and the second conductive electrode are independently indium tin oxide (ITO), aluminum-doped zinc oxide (AZO) or fluorine-doped tin dioxide (FTO). The present invention has no special limitation on the thickness of the first conductive electrode and the second conductive electrode, and parameters well known to those skilled in the art can be used.

[0060] In the present invention, the thickness of the electrochromic material in the electrochromic device is preferably 0.01-1 mm, specifically 0.01, 0.05, 0.1, 0.2, 0.5 or 1 mm.

[0061] In the present invention, the first conductive electrode and the second conductive electrode are preferably coated with conductive glue. The present invention has no special limitation on the type and coating amount of the conductive glue, and a solution well known to those skilled in the art can be adopted.

[0062] The present invention also provides a method for preparing the electrochromic device described in the above technical solution, comprising the following steps:

[0063] A spacing groove is placed on the surface of the first conductive electrode, and then the electrochromic material is placed in the spacing groove, and then covered with the second conductive electrode to obtain the electrochromic device.

[0064] In the present invention, the material of the spacing groove is preferably adhesive tape, polydimethylsiloxane (PDMS), light-curable resin or thermosetting resin.

[0065] The present invention also provides the application of the electrochromic device described in the above technical solution in the fields of smart windows and reflective displays.

[0066] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. 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.

[0067] Example 1

[0068] The preparation method of the electrochromic material based on the principle of metal electrodeposition is as follows:

[0069] 1. Preparation of polyacrylamide hydrogel: 1.5 g acrylamide was dissolved in 20 mL deionized water, 2 mg N, N'-methylenebisacrylamide and 3 mg ammonium persulfate were added to obtain a clear precursor solution, and then the solution was degassed in a vacuum chamber. After the above treatment was completed, 4 mg N, N, N'-, N'-tetramethylethylenediamine was added, and the solution was placed in an oven and baked at 60 ° C for 12 h.

[0070] 2. Preparation of metal electrodeposition aqueous solution: First weigh 60 mg of anhydrous copper chloride, 50 mg of anhydrous bismuth chloride and 500 mg of lithium bromide, add 4 mL of 1.2 mol / L hydrochloric acid solution, and finally add deionized water and stir thoroughly to make a 10 mL solution.

[0071] 3. Preparation of electrochromic material: The above metal electrodeposition aqueous solution and the hydrogel are placed in the same container at a volume ratio of 1:1, sealed and allowed to stand for 12 hours, to obtain an electrochromic material based on the metal electrodeposition principle, such as Figure 2 As shown, the liquid metal electrodeposition aqueous solution has been successfully adsorbed into the hydrogel and remains colorless and transparent.

[0072] 4. Preparation of electrochromic devices

[0073] The structure of electrochromic hydrogel device is as follows Figure 3As shown in the figure, a 0.2 mm spacing groove is prepared between two transparent conductive electrodes of indium tin oxide by using electrochemically inert material polydimethylsiloxane, and then the prepared electrochromic material is placed in the spacing groove, and the surfaces of the two transparent conductive electrodes are coated with conductive glue to obtain an electrochromic device. The device can achieve effective regulation of transmittance under voltage control ( Figure 4 ), and can also adjust the device to achieve reversible switching between colorless and neutral black ( Figure 5 ).

[0074] Example 2

[0075] The same as Example 1, the only difference is that the electrochromic material is prepared by using the metal electrodeposition aqueous solution and the hydrogel in a volume ratio of 1:2.

[0076] The electrochromic material obtained is Figure 6 As shown, the liquid metal electrodeposition aqueous solution has been successfully adsorbed into the hydrogel and remains colorless and transparent.

[0077] Figure 7 The transmittance spectra of the electrochromic device of Example 2 at different voltages show that the transmittance of the device can be effectively regulated under voltage control.

[0078] Example 3

[0079] The same as Example 1, the only difference is that no copper ions are added to the metal electrodeposition aqueous solution, and only bismuth ions are used as active deposition metal.

[0080] The prepared hydrogel device can achieve colorless-black switching ( Figure 8 ), and the regulation of visible spectrum transmittance ( Fig. 9 ).

[0081] Comparative Example

[0082] The preparation of the metal electrodeposition aqueous solution is the same as in Example 1.

[0083] Preparation of electrochromic device from metal electrodeposition aqueous solution: The same as the preparation of electrochromic device in 4. Example 1, except that the electrochromic material is replaced by metal electrodeposition aqueous solution.

[0084] Figure 8 The transmittance spectra of the electrochromic device of the comparative example at different voltages show that the transmittance can be effectively regulated under voltage control ( Fig.10 ), and can also adjust the device to achieve reversible switching between colorless and neutral black ( Fig.11 ). However, due to the intrinsic fluidity of the liquid, the device is prone to leakage and bubbles, and its application is limited by problems such as safety and transportability.

[0085] In summary, the present invention can solve the problem that the existing metal electrodeposition electrochromic material system usually exists in liquid form when used and is difficult to use. By combining the hydrogel with the metal electrodeposition solution, the hydrogel is given electrochromic properties, thereby improving its safety and transportability, and enhancing the application value of the electrochromic material.

[0086] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. 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, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing an electrochromic material based on the principle of metal electrodeposition, characterized in that: The following steps are involved: mixing a soluble metal salt, an electrolyte and water to obtain a metal electrodeposition aqueous solution; The metal electrodeposition aqueous solution is poured into the hydrogel to obtain the electrochromic material.

2. The preparation method according to claim 1, characterized in that: The metal ions in the soluble metal salt include one or more of copper ions, zinc ions, bismuth ions and silver ions.

3. The preparation method according to claim 1, characterized in that: The hydrogel includes one or more of polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, polyethylene oxide and polyhydroxyethyl methacrylate.

4. The preparation method according to claim 1, characterized in that: The concentration of metal ions in the metal electrodeposition aqueous solution is 1-100 g / L.

5. The preparation method according to claim 4, characterized in that: The volume ratio of the metal electrodeposition aqueous solution to the hydrogel is 1:1-3.

6. The preparation method according to claim 1, characterized in that: The electrolyte includes one or more of a lithium salt, a sodium salt, and a potassium salt.

7. The preparation method according to claim 1, characterized in that: The mixing also includes adding an inorganic acid.

8. The electrochromic material based on the metal electrodeposition principle obtained by the preparation method according to any one of claims 1 to 7.

9. Application of the electrochromic material based on the metal electrodeposition principle as claimed in claim 8 in anti-glare rearview mirrors, building curtain walls, car skylights, electronic tags and electronic billboards.

10. An electrochromic device, characterized in that: The method comprises a first conductive electrode, the electrochromic material according to claim 8 and a second conductive electrode which are stacked in sequence.

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