A conjugated polymer and a preparation method and application thereof

Abstract

The application discloses a conjugated polymer of chlorobenzene, o-dichlorobenzene or m-dichlorobenzene and EDOT as well as a preparation method and application thereof, and belongs to the field of polymer electrochromic materials. By introducing chlorine atoms as intermediates in different active sites of benzene and EDOT as a strong electron-donating group, the obtained conjugated polymer has the characteristics of a wider redox peak, good optical contrast, fast response time, high coloring efficiency, good stability and the like.

Description

Technical Field

[0001] This invention belongs to the field of polymer electrochromic materials, specifically relating to a conjugated polymer, its preparation method, and its application. Background Technology

[0002] Electrochromism (EC) refers to the phenomenon where a material undergoes a reversible and stable change in its color or optical properties (absorbance / transmittance / reflectivity, etc.) under the influence of an applied voltage. Among electrochromic materials, electrochromic conjugated polymers (ECPs) have attracted much attention due to their advantages such as diverse colors, good processability, low cost, fast response speed, and high coloring efficiency, and have broad application prospects in fields such as smart windows, information encryption, electronic paper, spacecraft thermal control, and military camouflage.

[0003] Currently, many materials can serve as electrochromic intermediates, such as benzo[c][1,2,5]thiadiazole (BT), thiadiazole[3,4-c]pyridine, benzotriazole, thiophenepyrazine, and quinoline. However, reports on the use of benzene derivatives as intermediates are rare. Phenyl electrochromic materials have attracted attention due to their excellent electrochromic properties, ease of preparation, and excellent stability. Substitution on the phenyl unit plays a crucial role in finely tuning the photoelectric and electronic properties of polymers (band gap, molecular weight, inter- and intra-chain interactions, charge transport, etc.). Among all halogen substituents, fluorine is the most widely used element for fine-tuning polymer properties and has been very successful in improving polymer electrochromism. Despite these achievements, the fluorine exchange reaction of fluorinated materials has low yields and involves toxic intermediates, making the final materials expensive and not the best choice for large-scale industrial production.

[0004] Therefore, it is of great significance to provide a high-performance phenyl polymer electrochromic material that is low-cost, low-toxicity, and can be mass-produced. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a conjugated polymer. This conjugated polymer, by introducing chlorine atoms as conjugated intermediates and EDOT as a strong electron-donating group into different active sites of benzene, results in a conjugated polymer with a broader redox peak. When used in electrochromic materials, it exhibits good optical contrast, fast response time, high coloring efficiency, and good stability.

[0006] The present invention also proposes a method for preparing the above-mentioned conjugated polymer.

[0007] The present invention also proposes an electrochromic material.

[0008] The present invention also proposes an application of the above-mentioned conjugated polymer in electrochromic devices.

[0009] The present invention also proposes a method for preparing the above-mentioned conjugated polymer.

[0010] According to one aspect of the invention, a conjugated polymer is provided having any of the following molecular structural formulas:

[0011] .

[0012] In this invention, the substitution of chlorine atoms on the phenyl unit not only lowers the HOMO / LUMO energy levels of the monomer and its polymer, but also reduces the initial oxidation potential of the monomer. The chlorination strategy of this invention has several advantages in modulating the π-electron behavior of organic semiconductors: (1) As the second most electronegative element in the halogen group, chlorine atoms affect intermolecular and intramolecular interactions; (2) Chlorination of the phenyl unit can lower the HOMO and LUMO energy levels; (3) Chlorinated molecules are readily available and inexpensive.

[0013] The conjugated polymers of chlorobenzene, o-dichlorobenzene, or m-dichlorobenzene-EDOT provided by this invention have various positive effects on their photoelectric properties, energy levels, planarity, and crystallinity due to the presence of non-covalent halogen bonds. When used in electrochromic materials, they have the characteristics of low bandwidth, rich colors, fast response time, and high coloring efficiency.

[0014] According to another aspect of the present invention, a method for preparing the above-mentioned conjugated polymer is provided, wherein the conjugated polymer is prepared from an active precursor by an electrochemical polymerization method; the active precursor has any of the following structural formulas:

[0015] .

[0016] The preparation method of the present invention is simple, the raw materials are readily available, the production cost is low, and it is easy to carry out large-scale industrial production.

[0017] In some embodiments of the present invention, the preparation method of the active precursor includes: under the protection of an inert gas, carrying out a Stille / Suzuki cross-coupling reaction between an intermediate compound and a tin hydrocarbon compound of EDOT in a catalyst and a solvent to obtain the active precursor;

[0018] The intermediate compound is 1,4-dibromo-2,5-dichlorobenzene, 1,4-dibromo-2,3-dichlorotoluene, or 1,4-dibromo-2-chlorobenzene.

[0019] In some preferred embodiments of the invention, the protective atmosphere comprises nitrogen.

[0020] In some preferred embodiments of the present invention, the tin hydrocarbon compound of EDOT is 5-tributyltin-3,4-vinyldioxothiophene, namely tributyl(2,3-dihydro[3,4-b][1,4]dioxin-5-yl)tinane.

[0021] In some preferred embodiments of the present invention, the catalyst is at least one of tetraphenylphosphine palladium (Pd(PPh3)4) or bis(triphenylphosphine palladium dichloride (Pd(PPh3)2Cl2).

[0022] In some preferred embodiments of the present invention, the solvent includes at least one of toluene and N,N-dimethylformamide (DMF).

[0023] In some preferred embodiments of the present invention, the molar ratio of the intermediate compound, the tin hydrocarbon compound of EDOT, and the catalyst is 1:2~3:0.03~0.1; for example, the molar ratio of the intermediate compound, the tin hydrocarbon compound of EDOT, and the catalyst can be about 1:2.5:0.04, about 1:2.5:0.05, or about 1:2.5:0.07.

[0024] In some preferred embodiments of the present invention, the reaction temperature is 100°C to 120°C; for example, it can be about 100°C, about 105°C, about 110°C or about 120°C.

[0025] In some preferred embodiments of the present invention, the reaction time is 24h to 48h; for example, it can be about 24h, about 28h, about 32h, about 36h, about 40h, or about 48h.

[0026] According to some specific embodiments of the present invention, an active precursor is prepared by any of the following reaction equations.

[0027] ,

[0028] , .

[0029] In some embodiments of the present invention, the method for preparing the active precursor further includes a step of purifying the product obtained from the reaction, including but not limited to rotary evaporation, vacuum distillation, and column chromatography (e.g., through a silica gel chromatography column).

[0030] In some preferred embodiments of the present invention, the electrochemical polymerization method includes using a solution containing the active precursor as an electrolyte solution, and electrodepositing the conjugated polymer using a potentiostatic method, a current-constant method, or a cyclic voltammetry method to obtain a thin film material.

[0031] In some preferred embodiments of the present invention, the electrolyte solution further includes a solvent.

[0032] In some more preferred embodiments of the present invention, the solvent includes at least one of dichloromethane (CH2Cl2), chloroform (CHCl3), or acetonitrile (MeCN).

[0033] In some preferred embodiments of the present invention, the electrolyte solution further contains a supporting electrolyte.

[0034] In some preferred embodiments of the present invention, the supporting electrolyte includes at least one of tetrabutylammonium hexafluorophosphate (Bu4NPF6), tetrabutylammonium tetrafluoroborate (Bu4NBF4), or lithium perchlorate (LiClO4).

[0035] In some preferred embodiments of the present invention, the concentration of the active precursor in the electrolyte solution is 0.001~0.01 mol. L -1 For example, approximately 0.001 mol L -1 Approximately 0.002 mol L -1 Approximately 0.005 mol L -1 or approximately 0.008 mol L -1 Approximately 0.01 mol L -1 .

[0036] In some preferred embodiments of the present invention, the concentration of the supporting electrolyte is 0.05~0.15 mol. L -1 Preferably, the concentration of the supporting electrolyte is 0.075~0.125 mol. L -1 In a more preferred embodiment, the concentration of the supporting electrolyte is approximately 0.1 mol. L -1 .

[0037] In some specific embodiments of the present invention, the above-mentioned benzene derivative conjugated with EDOT is prepared by one of the following reaction equations:

[0038] ,

[0039] ,

[0040] .

[0041] In some embodiments of the present invention, the electrochemical polymerization method is carried out in a three-electrode system consisting of a reference electrode, a counter electrode, and a working electrode.

[0042] In some preferred embodiments of the present invention, the working electrode includes a glassy carbon electrode / ITO conductive glass, the counter electrode includes a platinum wire, and the reference electrode includes an Ag / AgCl electrode.

[0043] In some preferred embodiments of the present invention, the electrochemical polymerization method employs a potentiostatic method for electrodeposition.

[0044] In some more preferred embodiments of the present invention, the electrodeposition potential is 0.8V to 1.2V; for example, it can be about 0.8V, about 0.9V, about 1.0V, about 1.1V or about 1.2V; preferably 0.8V to 1.0V.

[0045] In some more preferred embodiments of the present invention, the electrodeposition time is 80s to 200s; for example, electrodeposition for about 80s, about 100s, about 120s, about 140s, about 160s, about 180s or about 200s; preferably 100-160s.

[0046] In some more preferred embodiments of the present invention, the electrodeposition potential is about 0.9V and the time is about 120s.

[0047] According to another aspect of the present invention, an electrochromic material is provided, comprising the above-described conjugated polymer or the conjugated polymer prepared by the above-described preparation method.

[0048] According to another aspect of the present invention, the application of the above-described conjugated polymer or the conjugated polymer prepared by the above-described preparation method in electrochromic devices is proposed. The electrochromic devices include, but are not limited to, electrochromic glass.

[0049] The beneficial technical effects of this invention are as follows:

[0050] 1. The conjugated polymer of the present invention has a conjugated structure, and the polymer band gap can be adjusted by the π-π* conjugation strength, thereby changing the color of the polymer.

[0051] 2. The conjugated polymers of this invention possess excellent planarity based on benzene. Compared to traditional intermediates, chlorobenzene, o-dichlorobenzene, and m-dichlorobenzene are readily available and more economical, making them more promising for practical applications. The conjugated polymers of benzene derivatives combined with the strongly electron-donating group of 3,4-ethylenedioxythiophene (EDOT) exhibit shorter response times, better coloring efficiency, superior optical contrast, and more pronounced color changes, as characterized by electrochromic properties. Attached Figure Description

[0052] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0053] Figure 1 P(Y2Cl-EDOT) of Example 1 in MeCN-Bu4NPF6 (0.1 mol•L) -1 ) spectroelectrochemical diagrams of the system.

[0054] Figure 2 The transmittance-time curves of P(Y2Cl-EDOT) in Example 1 at 537nm, 890nm, and 1100nm are shown.

[0055] Figure 3 To implement P(T2Cl-EDOT) in MeCN-Bu4NPF6 (0.1 mol•L), -1 ) spectroelectrochemical diagrams of the system.

[0056] Figure 4 The transmittance-time curves of P(T2Cl-EDOT) in Example 2 at 465nm, 730nm and 1100nm are shown.

[0057] Figure 5 To implement 3 P(Cl-EDOT) in MeCN-Bu4NPF6 (0.1 mol•L -1 ) spectroelectrochemical diagrams of the system.

[0058] Figure 6 The transmittance-time curves of P(Cl-EDOT) in Example 3 at 465nm, 690nm, and 1100nm are shown. Detailed Implementation

[0059] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0060] As used herein, when used in conjunction with numerical values, the term "about" means a set or range of values. For example, "about" means a range of values ​​that includes ±10%, ±5%, ±2%, ±1%, ±0.5%, ±0.2%, or ±0.1% of that value. In one embodiment, the term "about" refers to a range of values ​​that are 5% more or less than a specific value. In another embodiment, the term "about" refers to a range of values ​​that are 2% more or less than a specific value. In yet another embodiment, the term "about" refers to a range of values ​​that are 1% more or less than a specific value.

[0061] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used are commercially available unless otherwise specified. Unless otherwise specified, the same parameter values ​​are used in all embodiments. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0062] In this invention, coloring efficiency refers to the ratio of the change in absorbance of an electrochromic material at a given wavelength to the change that results in the injection or extraction of all electrons.

[0063] For an electrochromic material, coloring efficiency is an important parameter for evaluating its performance. Studying the coloring efficiency of conductive polymers requires considering the electrochemical and spectral changes of the electrochromic film. The calculation formula is as follows:

[0064] OD=log(T ox / T red (1)

[0065] Q d =(Q ox +Q red ) / S(2)

[0066] CE = ΔOD / Q d (3)

[0067] Among them, T ox T represents the transmittance of the electrochromic material in its oxidized state. red Q represents the transmittance of the electrochromic material in its reduced state. ox Q represents the amount of charge during the oxidation process. red denoted as , where is the amount of charge during the reduction process; S is the area of ​​the working electrode.

[0068] Example 1

[0069] (1) Synthesis of Y2Cl-EDOT active precursor

[0070]

[0071] Under a nitrogen atmosphere, 2,5-dibromo-1,4-dichlorobenzene (1.64 mmol, 0.5 g), tributyl(2,3-dihydro[3,4-b][1,4]dioxin-5-yl)stanane (4.1 mmol, 1.772 g), and catalyst Pd(PPh3)2Cl2 (0.076 mmol, 0.066 g) were placed in a 250 mL single-necked flask, and dry toluene (Tol) (80 mL) was added. The mixture was stirred until homogeneous, and the mixture was heated to 120°C and refluxed for 48 hours. After cooling, toluene was removed by rotary evaporation; the mixture was extracted with dichloromethane, and the organic layer was washed with pure water. The solvent was then removed by vacuum distillation and rotary evaporation. The mixture was separated by silica gel column chromatography with DCM:PE = 1:3 as the eluent, and a white powder product Y2Cl-EDOT was obtained.

[0072] (2) Electrochemical synthesis of P(Y2Cl-EDOT) conjugated polymer

[0073]

[0074] Electrochemical polymerization was carried out in a three-electrode system, with a silver / silver chloride electrode as the reference electrode, a platinum wire as the counter electrode, and an ITO glass electrode as the working electrode. 10 mL of dichloromethane was used as the solvent, Y₂Cl-EDOT (0.0043 g, 0.01 mmol) as the monomer, and tetrabutylammonium hexafluoride (0.3874 g, 1 mmol) as the supporting electrolyte. Polymerization was performed using a potentiostatic method at a polymerization potential of 0.93 V, a scan rate of 100 mV / s, and a polymerization time of 120 s. The electrodeposited polymer film was immersed and rinsed with acetonitrile to remove the electrolyte and precursor from the polymer. The resulting polymer film was then placed in MeCN-Bu₄NPF₆ (0.1 mol•L₂). -1 The system was characterized by spectroelectrochemical methods.

[0075] (3) Study on electrochromic properties

[0076] (i) combination Figure 1 The color change of the polymer material was observed with the naked eye. It can be seen that as the potential increases, the color of the polymer material changes from brown to blue. This is because the neutral polymer material has an absorption peak in both the violet and red light regions, resulting in a brown color. After oxidation, the absorption peaks in the violet and red light regions gradually weaken and eventually disappear completely. Therefore, the polymer material in the completely undoped state appears brown, while the doped state appears blue.

[0077] (ii) The response time and coloring efficiency calculated from the time-transmittance curve are shown in Table 1.

[0078] Table 1 Electrochromic parameters of P(Y2Cl-EDOT)

[0079]

[0080] This invention investigates the optical transmittance of P(Y₂Cl-EDOT) at wavelengths of 537 nm, 890 nm, and 1100 nm using a time-lapse absorption method. During the experiment, the sawtooth wave period of potential versus time was 5 s. Figure 2 As shown, the polymer material exhibits certain optical contrast and good optical stability at all three wavelengths. Furthermore, the optical transmittance has a significant impact on the color change of the polymer material, which can transform from brown in a completely dedoped state to a deep blue in a doped state.

[0081] Example 2

[0082] (1) Synthesis of T2Cl-EDOT active precursor

[0083]

[0084] Under a nitrogen atmosphere, 1,4-dibromo-2,3-dichlorobenzene (1.64 mmol, 0.5 g), tributyl(2,3-dihydro[3,4-b][1,4]dioxin-5-yl)stanane (4.1 mmol, 1.772 g), and catalyst Pd(PPh3)2Cl2 (0.076 mmol, 0.066 g) were placed in a 250 mL single-necked flask, and dry toluene (80 mL) was added. The mixture was stirred until homogeneous and heated to 120°C under reflux for 48 hours. After cooling, toluene was removed by rotary evaporation; the mixture was extracted with dichloromethane, and the organic layer was washed with pure water. The solvent was then removed by vacuum distillation and rotary evaporation. The product was separated by silica gel column chromatography with DCM:PE = 1:3 as the eluent, yielding a white powder product T2Cl-EDOT.

[0085] (2) Electrochemical synthesis of P(T2Cl-EDOT) conjugated polymer

[0086]

[0087] Electrochemical polymerization was carried out in a three-electrode system, with a silver / silver chloride electrode as the reference electrode, a platinum wire as the counter electrode, and glassy carbon as the working electrode. 10 mL of dichloromethane was used as the electrolyte, T₂Cl-EDOT (0.0043 g, 0.01 mmol) as the monomer, and tetrabutylammonium hexafluoride (0.3874 g, 1 mmol) as the supporting electrolyte. Polymerization was performed using a potentiostatic method at a polymerization potential of 0.9 V, a scan rate of 100 mV / s, and a polymerization time of 120 s. The electrodeposited polymer film was immersed and rinsed with acetonitrile to remove the electrolyte and precursor from the polymer. The resulting polymer film was then placed in MeCN-Bu₄NPF₆ (0.1 mol•L₂). -1 The system was characterized by spectroelectrochemical methods.

[0088] (3) Study on electrochromic properties

[0089] (i) combination Figure 3 The color change of the polymer material was observed with the naked eye. It can be seen that as the potential increases, the color of the polymer material changes from cyan to blue. This is because the neutral polymer material has an absorption peak in both the violet and red light regions, and the neutral polymer material appears blue. After the polymer material is oxidized, the absorption peaks in the violet and red light regions gradually weaken and eventually disappear completely. Therefore, the polymer material in the completely undoped state appears cyan, while the doped polymer material appears blue.

[0090] (ii) The response time and coloring efficiency calculated from the time-transmittance curve are shown in Table 2.

[0091] Table 2 Electrochromic parameters of P(T2Cl-EDOT)

[0092]

[0093] The optical transmittance of P(T₂Cl-EDOT) was studied using chronoamperometry at wavelengths of 465 nm, 730 nm, and 1100 nm. During the experiment, the time interval between potential step changes was 5 s. Figure 4 As shown, the polymer material exhibits certain optical contrast and good optical stability at all three wavelengths. Furthermore, the optical transmittance has a significant impact on the color change of the polymer material, which can transform from cyan in a completely dedoped state to blue in a doped state.

[0094] Example 3

[0095] (1) Synthesis of Cl-EDOT active precursor

[0096]

[0097] Under a nitrogen atmosphere, 2,5-dibromo-chlorobenzene (1.85 mmol, 0.50 g), 2-tin-butyl-3-methylthiophene (4.64 mmol, 2.0 g), and catalyst Pd(PPh3)2Cl2 (0.074 mmol, 0.086 g) were placed in a 250 mL single-necked flask, and dry toluene (80 mL) was added. The mixture was stirred until homogeneous and heated to 120°C under reflux for 48 hours. After cooling, toluene was removed by rotary evaporation; the organic layer was extracted with dichloromethane, washed with pure water, and then the solvent was removed by vacuum distillation and rotary evaporation. Separation was performed using a silica gel column with DCM:PE = 1:3 as the eluent, yielding a white powdery product, Cl-EDOT.

[0098] (2) Electrochemical synthesis of P(Cl-EDOT) polymer

[0099]

[0100] Electrochemical polymerization was carried out in a three-electrode system, with a silver / silver chloride electrode as the reference electrode, a platinum wire as the counter electrode, and glassy carbon as the working electrode. 10 mL of dichloromethane was used as the electrolyte, Cl-EDOT (0.0039 g, 0.01 mmol) as the monomer, and tetrabutylammonium hexafluoride (0.3874 g, 1 mmol) as the supporting electrolyte. Polymerization was performed using a potentiostatic method at a polymerization potential of 1.05 V, a scan rate of 100 mV / s, and a polymerization time of 120 s. The electrodeposited polymer film was immersed and rinsed with acetonitrile to remove the electrolyte and precursor from the polymer. The resulting polymer film was then placed in MeCN-Bu4NPF6 (0.1 mol•L⁻¹). -1 The system was characterized by spectroelectrochemical methods.

[0101] (3) Study on electrochromic properties

[0102] (iii) Combination Figure 5 The color change of the polymer material was observed with the naked eye. It can be seen that as the potential increases, the color of the polymer material changes from yellow to blue. This is because the neutral polymer material has an absorption peak in both the violet and red light regions, hence its yellow color. After the polymer material is oxidized, the absorption peaks in the violet and red light regions gradually weaken and eventually disappear completely. Therefore, the polymer material in the completely undoped state appears yellow, while the doped state appears blue.

[0103] (iv) The response time and coloring efficiency calculated from the time-transmittance curve are shown in Table 3.

[0104] Table 3 Electrochromic parameters of P(Cl-EDOT)

[0105]

[0106] The optical transmittance of P(Cl-EDOT) at wavelengths of 465 nm, 690 nm, and 1100 nm was studied using a time-lapse absorption method. During the experiment, the time interval between potential step changes was 5 s. Figure 6 As shown, the polymer material exhibits certain optical contrast and good optical stability at all three wavelengths. Furthermore, the optical transmittance has a significant impact on the color change of the polymer material, which can transform from cyan in a completely dedoped state to blue in a doped state.

[0107] The absorption site of a polymer determines its color, which is of great significance for preparing electrochromic polymers of various colors. Response time is also an important parameter for electrochromic materials, as it reveals the speed at which dopant ions enter the polymer backbone during the doping process. As can be seen from Tables 1, 2, and 3, the conjugated polymer prepared in this invention has a fast response time and high coloring efficiency when used for electrochromism.

[0108] In summary, the conjugated polymer of this invention, as an electrochromic material, exhibits a stable and reversible color change to yellow or dark blue under an applied voltage. Furthermore, it possesses excellent electrochromic properties, including fast response time, high coloring efficiency, and good optical transmittance, making it widely applicable in electrochromic devices or products.

[0109] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A conjugated polymer, characterized in that, It has any of the following molecular structural formulas: 。 2. The method for preparing the conjugated polymer as described in claim 1, characterized in that, The conjugated polymer is prepared from an active precursor by electrochemical polymerization; the active precursor has any of the following structural formulas: 。 3. The preparation method according to claim 2, characterized in that, The method for preparing the active precursor includes: under the protection of an inert gas, carrying out a Stille / Suzuki cross-coupling reaction between an intermediate compound and a tin hydrocarbon compound of EDOT in a catalyst and a solvent to obtain the active precursor; The intermediate compound is 1,4-dibromo-2,5-dichlorobenzene, 1,4-dibromo-2,3-dichlorotoluene, or 1,4-dibromo-2-chlorobenzene.

4. The preparation method according to claim 3, characterized in that, The inert gas is argon; And / or, the tin hydrocarbon compound of the EDOT is 5-tributyltin-3,4-vinyldioxothiophene; And / or, the catalyst is at least one of tetraphenylphosphine palladium or bis(triphenylphosphine) palladium dichloride; And / or, the solvent includes at least one of toluene and N,N-dimethylformamide.

5. The preparation method according to claim 3, characterized in that, The molar ratio of intermediate compounds, tin hydrocarbon compounds of EDOT, and catalyst is 1:2~3:0.03~0.1; And / or, the temperature of the reaction is 100℃~120℃; And / or, the reaction time is 24h to 48h.

6. The preparation method according to claim 2, characterized in that, The electrochemical polymerization method includes using a solution containing the active precursor as an electrolyte solution, and electrodepositing the conjugated polymer thin film material using a constant potential method, a constant current method, or a cyclic voltammetry method. Alternatively, the electrochemical polymerization method is carried out in a three-electrode system consisting of a reference electrode, a counter electrode, and a working electrode; the working electrode comprises a glassy carbon electrode / ITO conductive glass, the counter electrode comprises a platinum wire, and the reference electrode comprises an Ag / AgCl electrode.

7. The preparation method according to claim 6, characterized in that, The electrolyte solution further includes a solvent; the solvent includes at least one of dichloromethane, trichloromethane, or acetonitrile; And / or, the electrolyte solution further contains a supporting electrolyte; the supporting electrolyte includes at least one of tetrabutylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, or lithium perchlorate; And / or, the concentration of the active precursor in the electrolyte solution is 0.001~0.01 mol. L -1 ; Alternatively, the concentration of the supporting electrolyte in the electrolyte solution is 0.05~0.15 mol. L -1 .

8. The preparation method according to claim 6, characterized in that, The electrochemical polymerization method employs a potentiostatic electrodeposition method. The electrodeposition potential is 0.8V~1.2V; and / or the electrodeposition time is 80s~200s.

9. An electrochromic material, characterized in that, It includes the conjugated polymer of claim 1 or the conjugated polymer prepared by any one of claims 2-8.

10. The application of the conjugated polymer as described in claim 1 or the conjugated polymer prepared by any one of claims 2-8 in electrochromic devices.

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