Thermosetting viologen electrochromic solution and electrochromic device

Abstract

The application provides a thermosetting viologen electrochromic solution and an electrochromic device. The thermosetting viologen electrochromic solution comprises the following components at the following concentrations: 1.5-4.5 g / mL of a diepoxy functional group molecule, 0.5-0.8 g / mL of an anhydride curing agent, 0.1-0.4 g / mL of a viologen compound, and 0.05-0.3 g / mL of a counter electrode material; the diepoxy functional group molecule is at least one selected from bisphenol f diglycidyl ether, bisphenol a diglycidyl ether and bisphenol s diglycidyl ether. The electrochromic device comprises a solid electrochromic layer formed by curing the thermosetting electrochromic solution. The application optimizes the formula, so that the electrochromic solution can achieve thermal curing while ensuring good electrochromic performance, solves the problems of easy leakage and poor safety of the viologen electrochromic device, and can be thermally cured and formed, avoiding the potential adverse effects of the ultraviolet curing method on the performance of the device.

Description

Technical Field

[0001] This invention belongs to the field of electrochromic technology, specifically relating to a thermosetting violet electrochromic solution and an electrochromic device. Background Technology

[0002] Electrochromism refers to the phenomenon where the optical properties (reflectivity, transmittance, absorptivity, etc.) of a material undergo stable and reversible color changes under the influence of an applied electric field. This manifests as reversible changes in color and transparency. Materials exhibiting electrochromic properties are called electrochromic materials, and devices made from electrochromic materials are called electrochromic devices.

[0003] Viologen compounds are widely used electrochromic materials due to their readily available raw materials and rich variety of color changes. However, viologen-based electrochromic devices are generally in liquid or gel states, leading to drawbacks such as easy leakage and solvent evaporation. Furthermore, existing viologen-based electrochromic devices have a sandwich structure of "electrochromic layer - counter electrode material layer - electrolyte layer," which cannot achieve integration. In addition, they are typically cured using ultraviolet light, which has a potential adverse effect on device performance. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a thermosetting violet electrochromic solution, which can be prepared by thermosetting to obtain an integrated thermosetting electrochromic device.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A thermosetting viologen electrochromic solution comprises the following components at the following concentrations: 1.5–4.5 g / mL diepoxy functional group molecules, 0.5–0.8 g / mL acid anhydride curing agent, 0.1–0.4 g / mL viologen compound, and 0.05–0.3 g / mL counter electrode material;

[0007] The diepoxy functional group molecule is selected from at least one of bisphenol f diglycidyl ether, bisphenol a diglycidyl ether, and bisphenol S diglycidyl ether.

[0008] In some embodiments, the thermosetting viologen electrochromic solution is characterized by comprising the following components at concentrations: 2.5–4 g / mL diepoxy functional group molecules, 0.55–0.7 g / mL acid anhydride curing agent, 0.15–0.35 g / mL viologen compound, and 0.05–0.2 g / mL counter electrode material.

[0009] In some embodiments, the anhydride curing agent is selected from at least one of pyromellitic dianhydride, phthalic anhydride, and hexahydrophthalic anhydride.

[0010] In some embodiments, the viologen compound is selected from at least one of methyl viologen, ethyl viologen, heptyl viologen, phenyl viologen, and p-trifluoromethylphenyl viologen.

[0011] In some embodiments, the counter electrode material is selected from at least one of 10-methylphenothiazine, ferrocene, and benzoquinone small molecule compounds.

[0012] In some embodiments, the solvent of the thermosetting violane electrochromic solution is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, methanol, acetonitrile, acetone, chlorobenzene, ethyl acetate, and isopropyl acetate.

[0013] The present invention also provides an electrochromic device comprising a solid electrochromic layer formed by curing the above-described thermosetting electrochromic solution.

[0014] In some embodiments, the thickness of the solid electrochromic layer is 20 μm to 200 μm.

[0015] In some embodiments, the electrochromic device includes a first FTO conductive glass and a second FTO conductive glass, with the solid electrochromic layer disposed between the first FTO conductive glass and the second FTO conductive glass.

[0016] The present invention also provides a method for preparing the electrochromic device as described above, comprising the following steps: (1) heat curing the thermosetting electrochromic solution at 60°C to 120°C for 20 min to 40 min to obtain the solid electrochromic layer; (2) placing the solid electrochromic layer between the first FTO conductive glass and the second FTO conductive glass and sealing it to obtain the electrochromic device.

[0017] This invention provides a thermosetting electrochromic solution. Through formulation optimization, the electrochromic solution can achieve thermosetting while maintaining good electrochromic performance. The diepoxy functional group molecules in the formulation enable the polymer to have a suitable degree of network cross-linking, thereby allowing the electrochromic molecules to diffuse. The presence of multiple hydroxyl groups enhances surface adhesion, helping to avoid the problems of interlayer shrinkage and tension mismatch between the electrochromic layer and the substrate. Furthermore, the combination of suitable curing agents and solvents allows the raw materials to form a homogeneous system, enabling the viologen compound and the counter electrode material molecules to transfer and diffuse between the polymer network and the electrode surface, achieving color change. This invention solves the problems of easy leakage and poor safety in viologen electrochromic devices, and it can be thermosetting, avoiding the potential adverse effects of UV curing on device performance. Detailed Implementation

[0018] Unless otherwise specified, the experimental methods described in the following embodiments of the present invention are generally performed under conventional conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the embodiments are commercially available products.

[0019] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0020] The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or device that includes a series of steps is not limited to the steps or modules listed, but may optionally include steps not listed, or may optionally include other steps inherent to such process, method, product, or device.

[0021] In this invention, "at least one" refers to one or more.

[0022] The following description is based on specific embodiments.

[0023] Example 1

[0024] This embodiment provides a thermosetting viologen electrochromic solution containing the following components: 5g bisphenol F diglycidyl ether, 1g pyromellitic dianhydride, 0.4g ethyl viologen, 0.15g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0025] Example 2

[0026] This embodiment provides a thermosetting viologen electrochromic solution comprising the following components: 6g bisphenol A diglycidyl ether, 1.1g hexahydrophthalic anhydride, 0.5g ethyl viologen, 0.15g 10-methylphenhiazine, and 1.5ml N,N-dimethylformamide.

[0027] Example 3

[0028] This embodiment provides a thermosetting viologen electrochromic solution containing the following components: 4g bisphenol S diglycidyl ether, 0.8g phthalic anhydride, 0.4g ethyl viologen, 0.2g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0029] Comparative Example 1

[0030] This comparative example provides a thermosetting viologen electrochromic solution, which differs from Example 1 in the type of polymer monomers and specifically contains the following components: 5g 1,3,5-triglycidyl-S-triazinetrione, 1g pyromellitic dianhydride, 0.4g ethyl viologen, 0.15g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0031] Comparative Example 2

[0032] This comparative example provides a thermosetting viologen electrochromic solution. Compared with Example 1, the amount of polymer monomer used is excessive. Specifically, it contains the following components: 7.8g bisphenol F diglycidyl ether, 1g pyromellitic dianhydride, 0.4g ethyl viologen, 0.15g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0033] Comparative Example 3

[0034] This comparative example provides a thermosetting viologen electrochromic solution. Compared with Example 1, the amount of polymer monomer used is too small. Specifically, it contains the following components: 1.6g bisphenol F diglycidyl ether, 1g pyromellitic dianhydride, 0.4g ethyl viologen, 0.15g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0035] Comparative Example 4

[0036] This comparative example provides a thermosetting viologen electrochromic solution. Compared with Example 1, the amount of anhydride curing agent is excessive. Specifically, it contains the following components: 5g bisphenol F diglycidyl ether, 1.4g pyromellitic dianhydride, 0.4g ethyl viologen, 0.15g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0037] Comparative Example 5

[0038] This comparative example provides a thermosetting viologen electrochromic solution. Compared with Example 1, the amount of anhydride curing agent is too small. Specifically, it contains the following components: 5g bisphenol F diglycidyl ether, 0.5g pyromellitic dianhydride, 0.4g ethyl viologen, 0.15g 10-methylphenthiazide, and 1.5ml N,N-dimethylformamide.

[0039] The electrochromic device is prepared using the electrochromic solution in the above embodiments and comparative examples, including the following steps: (1) The thermosetting electrochromic solution in the above embodiments and comparative examples is thermosetting at 100°C for 30 min to obtain a solid electrochromic layer with a thickness of 100 μm; (2) The solid electrochromic layer is placed between a first FTO conductive glass and a second FTO conductive glass and sealed to obtain the corresponding electrochromic device.

[0040] The state of the solid electrochromic layer formed by the electrochromic solution in each embodiment and comparative example was detected.

[0041] The transparency, coloring time, and fading time of the electrochromic devices prepared in the above embodiments and comparative examples were tested:

[0042] Transparency detection: The device is placed under an ultraviolet spectrophotometer to detect the initial transmittance of the solid-state device.

[0043] Coloring time and fading time were measured using an electrochemical workstation and a UV-Vis spectrophotometer, and the method was chronopotential method.

[0044] The results are shown in Table 1:

[0045] Table 1

[0046]

[0047] The results show that the electrochromic solution of the present invention (Examples 1-3) can be thermally cured, and the device has good response performance and good transparency. It can effectively avoid the leakage problem of liquid or gel electrochromic materials, as well as the potential adverse effects of ultraviolet curing on device performance.

[0048] Compared to Example 1, in Comparative Example 1, the polymer monomer 1,3,5-triglycidyl-S-triazinetrione in the electrochromic solution did not meet the requirements, resulting in the electrochromic device failing to color; in Comparative Example 2, the amount of polymer monomer in the electrochromic solution was excessive, resulting in the electrochromic device failing to color; in Comparative Example 3, the amount of polymer monomer in the electrochromic solution was insufficient, resulting in insufficient rigidity of the electrochromic device, which remained in a gel state, unable to form a solid state, lacking memory effect, and posing a risk of leakage; in Comparative Example 4, the amount of acid anhydride curing agent in the electrochromic solution was excessive, resulting in the electrochromic device failing to color; and in Comparative Example 5, the amount of acid anhydride curing agent in the electrochromic solution was insufficient, resulting in insufficient rigidity of the electrochromic device, which remained in a gel state, unable to form a solid state, lacking memory effect, and posing a risk of leakage.

[0049] In summary, through formulation optimization, this invention enables the electrochromic solution to maintain good electrochromic performance while achieving thermosetting, thus realizing the convenient and efficient fabrication of integrated solid-state electrochromic devices.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A thermosetting viologen electrochromic solution, characterized in that, The components contain the following concentrations: 1.5~4.5 g / mL diepoxy functional group molecules, 0.5~0.8 g / mL acid anhydride curing agent, 0.1~0.4 g / mL viologen compound, and 0.05~0.3 g / mL counter electrode material; The diepoxy functional group molecule is selected from at least one of bisphenol f diglycidyl ether, bisphenol a diglycidyl ether, and bisphenol S diglycidyl ether; The anhydride curing agent is selected from at least one of pyromellitic dianhydride, phthalic anhydride, and hexahydrophthalic anhydride.

2. The thermosetting violet electrochromic solution as described in claim 1, characterized in that, It contains the following components at the following concentrations: 2.5~4 g / mL diepoxy functional group molecules, 0.55~0.7 g / mL acid anhydride curing agent, 0.15~0.35 g / mL viologen compound, and 0.05~0.2 g / mL counter electrode material.

3. The thermosetting violet electrochromic solution as described in claim 1, characterized in that, The viologen compound is selected from at least one of methyl viologen, ethyl viologen, heptyl viologen, phenyl viologen, and p-trifluoromethylphenyl viologen.

4. The thermosetting violet electrochromic solution as described in claim 1, characterized in that, The counter electrode material is selected from at least one of 10-methylphenothiazine, ferrocene, and benzoquinone small molecule compounds.

5. The thermosetting violet electrochromic solution as described in claim 1, characterized in that, The solvent of the thermosetting violane electrochromic solution is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, methanol, acetonitrile, acetone, chlorobenzene, ethyl acetate, and isopropyl acetate.

6. An electrochromic device, characterized in that, The electrochromic device comprises a solid electrochromic layer formed by curing the thermosetting violet electrochromic solution according to any one of claims 1 to 5.

7. The electrochromic device as described in claim 6, characterized in that, The thickness of the solid electrochromic layer is 20μm~200μm.

8. The electrochromic device as described in claim 6, characterized in that, The electrochromic device includes a first FTO conductive glass and a second FTO conductive glass, with the solid electrochromic layer disposed between the first FTO conductive glass and the second FTO conductive glass.

9. The method for preparing the electrochromic device according to any one of claims 6 to 8, characterized in that, The process includes the following steps: (1) heat curing the thermosetting electrochromic solution at 60°C to 120°C for 20 min to 40 min to obtain the solid electrochromic layer; (2) placing the solid electrochromic layer between the first FTO conductive glass and the second FTO conductive glass and sealing it to obtain the electrochromic device.

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