Electrochromic material, electrochromic device and application thereof

Abstract

This application provides an electrochromic material, an electrochromic device, and their applications. The electrochromic material comprises a polymer of formula (I), wherein the structural units of the polymer of formula (I) are selected from A, B, C, and D; the number-average molecular weight of the polymer of formula (I) is 1,000 to 1,000,000; x, y, z, and w represent the molar percentages of A, B, C, and D in the polymer, respectively, where x ≥ 0, y > 0, z > 0, and w > 0. By selecting the polymer of formula (I) and adjusting the monomer ratio and the type and position of the substituents on the monomers, the electrochromic material can possess properties such as a large initial absorption wavelength, a narrow optical band gap, and a low initial oxidation potential, thereby improving the stability of the device while the electrochromic material can change color from black to transparent.

Description

Technical Field

[0001] This application relates to the field of electrochromic technology, and in particular to an electrochromic material, an electrochromic device, and their applications. Background Technology

[0002] Electrochromism refers to the formation of new optical transitions in electroactive substances during reversible electrochemical oxidation / reduction reactions. Electrochromic materials can be broadly classified into three categories: inorganic electrochromic materials, organic electrochromic materials, and transition metal complex electrochromic materials. The most widespread applications of electrochromic materials include rearview mirrors, safety glasses, displays, smart windows, optical shutters, optical data storage, and electronic paper. In recent years, organic electrochromic materials have become one of the key research areas in the field of electrochromic studies. Among them, organic conductive polymers are among the most representative organic electrochromic materials, such as polyarylamines, polythiophenes, and polypyrrole conductive polymers, which have received widespread attention.

[0003] CN110892001A discloses a black polythiophene-based random copolymer, obtained by high-temperature reaction in a degassed solvent catalyzed by K2CO3, PivOH, and Pd(OAc)2. Its initial absorption wavelength is approximately 800 nm, characterized by a small initial absorption wavelength, a large optical band gap, and a high initial oxidation potential. This results in a high required applied voltage after fabrication into devices, leading to poor material stability.

[0004] Therefore, developing a black electrochromic polymer with a large initial absorption wavelength, narrow band gap, and low oxidation potential is a key research focus in this field. Summary of the Invention

[0005] The purpose of this application is to provide an electrochromic material, an electrochromic device, and its application, so that the electrochromic material has the properties of a large initial absorption wavelength, a narrow optical band gap, and a low initial oxidation potential, thereby improving the stability of the device while the electrochromic material can change color from black to transparent. The specific technical solution is as follows:

[0006] The first aspect of this application provides an electrochromic material comprising a polymer of formula (I): ;

[0007] Wherein, the number-average molecular weight of the polymer in formula (I) is between 1,000 and 1,000,000; x, y, z, and w represent the molar percentages of A, B, C, and D in the polymer, respectively, where x ≥ 0, y > 0, z > 0, and w > 0; A, B, and C are selected from the following structural units: ;

[0008] D is a conjugated spacer group, and D is selected from at least one of D1 to D15: ; ; ; ;

[0009] Among them, R1, R2, R5, R6, R7, R8, R9, R 10 R 11 and R 12 Each is independently selected from hydrogen, C1-C 30 Alkyl, C3-C 30 Alkyl, C3-C 30 Alkynyl, C2-C 30 Alkyl carbonyl, C1-C 30 Alkoxy, C2-C 30 Alkoxycarbonyl, C1-C 30 Alkyl mercapto, C2-C 30 Alkylamino, C2-C 30 Alkylamide group, C2-C 30 Alkyl sulfonyl, C3-C 15 cycloalkyl, C1-C 30 Hydroxyalkyl, C3-C 30 Alkoxyalkyl, C6-C 14 Aryl, C7-C 30 Aryl group, C6-C 14 Aromatic amino, C7-C 30 Aryl (alkyl)amino, C6-C 14 arylalkoxy, C7-C 14 Aromatic amide group, C7-C 14 Alkyl ester group, C8-C 30 Aryloxyalkyl, C5-C7 saturated or unsaturated heterocyclic groups, C3-C 30 Polyether-based, C1-C 30 Fluoroalkyl groups and groups shown in formula (II), wherein R5 and R6 are not simultaneously represented as hydrogen; wherein, the C5-C7 saturated heterocyclic groups are selected from tetrahydrofuran, tetrahydropyrrole, and tetrahydrothiophene; the C5-C7 unsaturated heterocyclic groups are selected from pyridyl, furanyl, and thiophene; wherein, R3 and R4 are each independently selected from hydrogen, fluorine, bromine, iodine, and C1-C 30 Alkyl, C1-C 30 Alkoxy, C6-C 14 Aryl; .

[0010] In one embodiment of this application, the number-average molecular weight of the polymer of formula (I) is 3,000 to 50,000.

[0011] In one embodiment of this application, the polymer of formula (I) is any one of random copolymer, block copolymer or alternating copolymer.

[0012] In one embodiment of this application, 0 ≤ x < 92.5%, 3% ≤ y < 100%, 0 < z < 93%, 0 < w ≤ 90%, preferably, 5% ≤ x ≤ 40%, 10% ≤ y ≤ 30%, 10% ≤ z ≤ 50%, and 2% ≤ w ≤ 30%.

[0013] In one embodiment of this application, R1 and R2 are each independently selected from C1-C 30 Alkoxy, C1-C 30 Alkyl, C3-C 30 Alkoxyalkyl.

[0014] In one embodiment of this application, R3 and R4 are each independently selected from hydrogen, fluorine, and methyl.

[0015] In one embodiment of this application, the polymer of formula (I) is selected from at least one of donor-donor fragments, donor-acceptor fragments, donor-conjugated spacer fragments, acceptor-conjugated spacer fragments, and conjugated spacer fragments, wherein the donor-donor fragment is selected from at least one of AA, AC, and CC; the donor-acceptor fragment is selected from at least one of BA and BC; and the donor-conjugated spacer fragment is selected from AD1, AD2, AD3, AD4, AD5, AD6, AD7, AD8, AD9, AD10, AD11, AD12, AD13, and A. The receptor-conjugated spacer fragment is selected from at least one of D14, AD15, CD1, CD2, CD3, CD4, CD5, CD6, CD7, CD8, CD9, CD10, CD11, CD12, CD13, CD14, and CD15; the acceptor-conjugated spacer fragment is selected from at least one of BD1, BD2, BD3, BD4, BD5, BD6, BD7, BD8, BD9, BD10, BD11, BD12, BD13, BD14, and BD15; the conjugated spacer fragment is selected from at least one of D10 and D11. ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; .

[0016] In one embodiment of this application, the polymer of formula (I) is selected from the structures shown in I-1 to I-37: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;

[0017] o, p, r, t, q, s, u, v, m are the mole fractions of the corresponding structural segments, and o, p, r, t, q, s, u, v, m independently satisfy: 0≤o<1, 0≤p<1, 0≤r<1, 0≤t<1, 0≤q<1, 0≤s<1, 0≤u<1, 0≤v<1, 0≤m<1. Preferably, 0.1≤o≤0.5, 0.1≤p≤0.5, 0.1≤r≤0.8, 0.05≤t<0.3, 0.05≤q≤0.5, 0.15≤s≤0.85, 0.1≤u≤0.8, 0.03≤v≤0.5, 0.05≤m≤0.8.

[0018] In one embodiment of this application, the electrochromic material further includes a conductive material selected from at least one of indium tin oxide, zinc aluminum oxide, fluorine-doped tin oxide, silver nanowires, graphene, carbon nanotubes, silver nanoparticle ink, and organic conductive polymer; wherein the organic conductive polymer is selected from at least one of PEDOT:PSS, polyaniline, and polypyrrole, preferably, the organic conductive polymer is selected from PEDOT:PSS.

[0019] In one embodiment of this application, the initial absorption wavelength range in the neutral state is 840 nm to 1000 nm.

[0020] In one embodiment of this application, the initial oxidation potential in the neutral state is E. ox 0 <E ox <1.5.

[0021] In one embodiment of this application,

[0022] A second aspect of this application provides an electrochromic device comprising the electrochromic material of any of the foregoing embodiments.

[0023] The third aspect of this application provides the application of the electrochromic device of the second aspect of this application in the fields of automobile windows, anti-glare rearview mirrors, 3C products, building glass curtain walls, and eyeglasses.

[0024] The beneficial effects of this application are:

[0025] This application provides an electrochromic material and an electrochromic device. The electrochromic material comprises a polymer of formula (I); the structural units of the polymer are selected from A, B, C, and D. By selecting a polymer of formula (I) and adjusting the monomer ratio and the type and position of the substituents on the monomers, the electrochromic material can possess properties such as a large initial absorption wavelength, a narrow optical band gap, and a low initial oxidation potential, thereby enabling the electrochromic material to change from black to transparent. The electrochromic device provided in this application exhibits good stability.

[0026] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these accompanying drawings.

[0028] Figure 1 The cyclic voltammetry curve for P01;

[0029] Figure 2 The electrochemical spectrum of P01;

[0030] Figure 3 The UV-Vis absorption spectra of P01 in neutral and oxidized states;

[0031] Figure 4 The cyclic voltammetry curve for P02;

[0032] Figure 5 The electrochemical spectrum of PO2;

[0033] Figure 6 The UV-Vis absorption spectra of PO2 in neutral and oxidized states are shown.

[0034] Figure 7 The UV-Vis absorption spectra of P01 and P02 in the neutral state are shown. Detailed Implementation

[0035] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0036] To further enhance the electrochromic properties of organic conductive polymers, an effective strategy is to introduce electron donor-acceptor structures into the molecular design. This can effectively shorten the color-changing response time and improve cycle stability. Using the donor-acceptor method to design novel donor-acceptor electrochemical polymers (ECPs) can exhibit dual-band absorption in the visible light region, thus reflecting and / or transmitting colors that are typically difficult to achieve (such as saturated green). Furthermore, this structural design can theoretically broaden the HOMO and LUMO energy levels of the polymer, effectively reducing its band gap when sufficiently strong intermolecular forces are generated between functional groups. A reduced band gap can lower the operating voltage of the device, thereby helping to suppress performance degradation of the material or device.

[0037] The first aspect of this application provides an electrochromic material, characterized in that the electrochromic material comprises a polymer of polymeric formula (I): ;

[0038] The number-average molecular weight of the polymer in formula (I) is between 1,000 and 1,000,000;

[0039] x, y, z, and w represent the molar percentages of A, B, C, and D in the polymer, respectively, where x ≥ 0, y > 0, z > 0, and w > 0; A, B, and C are selected from the following structural units: ;

[0040] D is a conjugated spacer group, and D is selected from at least one of D1 to D15: ; ; ; ;

[0041] Among them, R1, R2, R5, R6, R7, R8, R9, R 10 R 11 and R 12 Each is independently selected from hydrogen, C1-C 30 Alkyl, C3-C 30 Alkyl, C3-C 30 Alkynyl, C2-C 30 Alkyl carbonyl, C1-C 30 Alkoxy, C2-C 30 Alkoxycarbonyl, C1-C 30 Alkyl mercapto, C2-C 30 Alkylamino, C2-C 30 Alkylamide group, C2-C 30 Alkyl sulfonyl, C3-C 15 cycloalkyl, C1-C 30 Hydroxyalkyl, C3-C 30 alkoxyalkyl, C6-C 14 Aryl, C7-C 30 Aryl group, C6-C 14 Aromatic amino, C7-C 30 Aryl (alkyl)amino, C6-C 14 arylalkoxy, C7-C 14 Aromatic amide group, C7-C 14 Alkyl ester group, C8-C 30 Aromatic oxyalkyl groups, C5-C7 saturated or unsaturated heterocyclic groups, C3-C 30 Polyether-based, C1-C 30 Fluoroalkyl groups and groups shown in formula (II), wherein R5 and R6 are not simultaneously represented as hydrogen; wherein, the C5-C7 saturated heterocyclic groups are selected from tetrahydrofuran, tetrahydropyrrole, and tetrahydrothiophene; the C5-C7 unsaturated heterocyclic groups are selected from pyridyl, furanyl, and thiophene; wherein, R3 and R4 are each independently selected from hydrogen, fluorine, bromine, iodine, and C1-C 30 Alkyl, C1-C 30 Alkoxy, C6-C 14 Aryl; .

[0042] Preferably, R1 and R2 are each independently selected from C1-C30 Alkoxy, C1-C 30 Alkyl, C3-C 30 Alkoxyalkyl.

[0043] Preferably, R3 and R4 are each independently selected from hydrogen, fluorine, and methyl. Those skilled in the art will understand that the above groups can be branched or straight-chain groups.

[0044] In one embodiment of this application, the number-average molecular weight of the polymer of formula (I) is 3,000 to 50,000.

[0045] In one embodiment of this application, the polymer of formula (I) is any one of random copolymer, block copolymer or alternating copolymer.

[0046] In one embodiment of this application, 0 ≤ x < 92.5%, 3% ≤ y < 100%, 0 < z < 93%, 0 < w ≤ 90%, preferably, 5% ≤ x ≤ 40%, 10% ≤ y ≤ 30%, 10% ≤ z ≤ 50%, and 2% ≤ w ≤ 30%. For example, the value of x can be 0, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 92%, or any value within the range of any two of the above values; the value of y can be 3%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 98%, or any value within the range of any two of the above values; the value of z can be 1.5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 92%; and the value of w can be 1.5%, 2%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 90%, or any value within the range of any two of the above values. By adjusting the molar percentage within the above ranges, the polymer color can be finely controlled. If w is greater than 90%, the absorption intensity of the resulting polymer in the short wavelength region (400nm to 560nm) will increase, resulting in a polymer with a yellowish color.

[0047] In one embodiment of this application, the polymer of formula (I) is selected from at least one of donor-donor fragments, donor-acceptor fragments, donor-conjugated spacer fragments, acceptor-conjugated spacer fragments, and conjugated spacer fragments; wherein the donor-donor fragment is at least one selected from AA, AC, and CC; the donor-acceptor fragment is at least one selected from BA and BC; and the donor-conjugated spacer fragment is selected from AD1 and AD2. At least one of AD3, AD4, AD5, AD6, AD7, AD8, AD9, AD10, AD11, AD12, AD13, AD14, AD15, CD1, CD2, CD3, CD4, CD5, CD6, CD7, CD8, CD9, CD10, CD11, CD12, CD13, CD14, and CD15; the acceptor-conjugated spacer fragment is selected from at least one of BD1, BD2, BD3, BD4, BD5, BD6, BD7, BD8, BD9, BD10, BD11, BD12, BD13, BD14, and BD15; the conjugated spacer fragment is selected from at least one of D10 and D11. ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; .

[0048] By introducing the aforementioned fragments, the polymer can achieve a neutral black state through fine-tuning of color via multiple donors and acceptors. In this mode, the multiple donors in the donor-donor unit work synergistically to more effectively "push" electrons, significantly increasing the HOMO energy level of the molecule and further reducing the oxidation potential of the material. Within the wide bandgap, the donor-donor unit absorbs high-energy photons (UV-blue light), contributing short-wavelength absorption peaks. The donor-acceptor unit lowers the LUMO energy level of the molecule, generating a stronger push-pull electron effect, reducing the bandgap, and contributing long-wavelength absorption peaks. The combined action of the donor-donor and donor-acceptor fragments achieves full-spectrum absorption in the visible light region, manifesting a neutral black state.

[0049] In one embodiment of this application, polymer (I) is selected from the structures shown in I-1 to I-37: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ；

[0050] Where o, p, r, t, q, s, u, v, and m are the mole fractions of the corresponding structural segments, and o, p, r, t, q, s, u, v, and m independently satisfy: 0≤o<1, 0≤p<1, 0≤r<1, 0≤t<1, 0≤q<1, 0≤s<1, 0≤u<1, 0≤v<1, 0≤m<1. Preferably, 0.1≤o≤0.5, 0.1≤p≤0.5, 0.1≤r≤0.8, 0.05≤t<0.3, 0.05≤q≤0.5, 0.15≤s≤0.85, 0.1≤u≤0.8, 0.03≤v≤0.5, and 0.05≤m≤0.8. For example, the value of o can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or any value within the range of any two of the above values; the value of p can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or any value within the range of any two of the above values; and the value of r can be 0, 0.1, 0.2, 0.3, 0.4, ... The values ​​of t and q are: 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or any value within the range of any two of the above values; t can be 0, 0.05, 0.1, 0.2, 0.29, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or any value within the range of any two of the above values; q can be 0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.98, or any value within the range of any two of the above values; q can be 0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.98, or any value within the range of any two of the above values. The values ​​of s, u, and u are all within the range of 0.8, 0.9, 0.95, 0.98, or any two of the above values. The values ​​of s, u, and u are all within the range of 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.85, 0.9, 0.98, or any two of the above values. The value of v can be any value within the range defined by the two values ​​mentioned above. The value of v can be 0, 0.03, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or any value within the range defined by the two values ​​mentioned above. The value of m can be 0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.98, or any value within the range defined by the two values ​​mentioned above. By adjusting the mole fraction of the structural segment within the above range, the color of the membrane can be precisely controlled.

[0051] In one embodiment of this application, the electrochromic material further includes a conductive material selected from at least one of indium tin oxide, zinc aluminum oxide, fluorine-doped tin oxide, silver nanowires, graphene, carbon nanotubes, silver nanoparticle ink, and organic conductive polymers. By selecting the above-mentioned conductive material, the specific surface area of ​​the composite material is increased, providing more electrochemical reaction active sites, mainly playing a role in improving electron conductivity. Ultimately, this significantly reduces the overall resistance of the material, enabling electrons to be rapidly and uniformly injected or extracted throughout the electrochromic film.

[0052] In this application, the organic conductive polymer is selected from at least one of PEDOT:PSS, polyaniline, and polypyrrole, and preferably, the organic conductive polymer is selected from PEDOT:PSS.

[0053] In this application, PEDOT:PSS is a polymer formed from poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate). This application does not impose any particular restrictions on PEDOT:PSS, polyaniline, or polypyrrole; those skilled in the art can select the appropriate type based on actual needs.

[0054] In one embodiment of this application, the electrochromic material has an initial absorption wavelength range of 840 nm to 1000 nm in the neutral state. Within this initial absorption wavelength range in the neutral state, the electrochromic material of this application allows for near-full-band absorption of visible light when no voltage is applied, thereby maintaining low visible light transmittance. In one embodiment of this application, the initial oxidation potential of the electrochromic material in the neutral state is E. ox 0 <E ox <1.5. The electrochromic material of this application has a low onset oxidation potential, which enables the material to change color at a lower driving voltage, thereby reducing the energy consumption of the device.

[0055] In this application, the electrochromic material has a band gap of E in the neutral state. g 1.0 <E g <2. The electrochromic material of this application has a narrow band gap, which can reduce the operating voltage of the device during operation, thereby helping to suppress the performance degradation of the material or device.

[0056] This application provides an electrochromic material and a method for preparing the same, comprising the following steps:

[0057] Under a nitrogen atmosphere, the desired monomer is added to the reaction vessel, followed by the catalyst; a vacuum is drawn, and then nitrogen is added back. This evacuation and nitrogen replacement process can be repeated. The degassed solvent is added to the reaction vessel and heated to 50°C–220°C for 0.5–48 hours. After the reaction is complete, the temperature is lowered to room temperature, and the reaction solution is purified, precipitated, filtered, washed, and dried to obtain the polymer.

[0058] In this application, a degassed solvent is obtained by bubbling the solvent with dry nitrogen gas to remove moisture and oxygen. This application does not have a particular limitation on the bubbling time, as long as the objective of this application is achieved; for example, bubbling for 15 minutes is acceptable. In one embodiment of this application, the catalyst is selected from at least one of K₂CO₃, PivOH, and Pd(OAc)₂.

[0059] In one embodiment of this application, the degassing solvent is selected from at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide.

[0060] A second aspect of this application provides an electrochromic device, characterized in that the electrochromic device comprises the electrochromic material of any of the foregoing embodiments. Therefore, the electrochromic device provided by this application requires a low applied voltage and exhibits good stability while achieving electrochromism.

[0061] In this application, the fabrication method of the electrochromic device is not particularly limited, and methods known to those skilled in the art can be used. For example, the electrochromic device of this application may include:

[0062] First electrode;

[0063] A second electrode is positioned relative to the first electrode;

[0064] The electrochromic material of this application is disposed on the first electrode and located between the first electrode and the second electrode;

[0065] A solid electrolyte is disposed between the electrochromic material and the second electrode;

[0066] A charge storage layer is disposed between the solid electrolyte and the second electrode.

[0067] This application does not impose any particular restrictions on the first electrode, as long as it can achieve the purpose of this application. For example, the first electrode can be selected from a transparent conductive electrode, a metallic conductive electrode, or a composite conductive electrode.

[0068] This application does not impose any particular restrictions on the solid electrolyte, as long as it can achieve the purpose of this application. For example, the solid electrolyte can be selected from at least one of Ta2O5, MgF, Li3N, LiPO4, LiBO2-Li2SO4, and LiTFSI.

[0069] This application does not impose any particular limitation on the charge storage layer, as long as it can achieve the purpose of this application. For example, the charge storage layer can be selected from vanadium oxide, binary oxide (e.g., IrO2, MnO, NiO and PrO2). x ), ternary oxides (e.g., Ce)x V y O z At least one of the following.

[0070] This application does not impose any particular restrictions on the second electrode, as long as it can achieve the purpose of this application. For example, the second electrode can be selected from a transparent conductive electrode, a metallic conductive electrode, or a composite conductive electrode.

[0071] The third aspect of this application provides the application of the electrochromic device of the second aspect of this application in the fields of automobile windows, anti-glare rearview mirrors, 3C products, building glass curtain walls, and eyeglasses. The specific method of use is not particularly limited and can be a method known in the art.

[0072] Example

[0073] The embodiments and comparative examples provided below illustrate the implementation of this application in more detail. Various tests and evaluations were conducted according to the methods described below. Furthermore, unless otherwise specified, "parts" and "%" are quality standards.

[0074] Test methods and equipment:

[0075] Gel permeation chromatography (GPC) test:

[0076] A Waters 1515 gel permeation chromatography (GPC) system equipped with a differential refractive index (RI) detector was used with tetrahydrofuran (THF) as the mobile phase and polystyrene as the standard to determine the molecular weight and distribution of the polymer, yielding the number-average molecular weight (Mn) and molecular weight distribution index (PDI).

[0077] Nuclear magnetic resonance hydrogen spectroscopy test ( 1 H NMR):

[0078] The 1H NMR spectrum of the polymer was measured using Bruker BioSpin GmbH. A 100 mg / mL solution was prepared using deuterated chloroform for the test.

[0079] Preparation of EC membranes: The polymer sample was dissolved in chloroform and then spin-coated onto the surface of ITO. After drying, the resulting EC membranes were subjected to performance testing.

[0080] CV Cyclic Voltammetry Test:

[0081] Cyclic voltammetry tests of the electrochromic thin film were performed using a Chenhua CHI600E electrochemical workstation. A platinum sheet electrode and an Ag / AgCl electrode were used as the auxiliary and reference electrodes, respectively. 0.1 M (mol / L) tetrabutylammonium hexafluorophosphate was dissolved in anhydrous acetonitrile as the supporting electrolyte. The electrochromic thin film was prepared as follows: 1 g of the electrochromic material was dissolved in 10 g of xylene and stirred thoroughly at room temperature. 5 g of the solution was then drop-coated onto an ITO substrate and spread evenly using a wire rod. The film was baked in a 100℃ oven for 20 min, and then cut into 3 cm × 3 cm pieces for testing.

[0082] Neutral and oxidized absorbance tests:

[0083] The absorption spectra of the electrochromic thin film in the neutral and oxidized states were measured using UV-Vis absorption spectroscopy. The electrochromic thin film was prepared as follows: 1 g of electrochromic material was dissolved in 10 g of xylene and stirred thoroughly at room temperature. 5 g of the solution was then drop-coated onto an ITO substrate and spread evenly using a wire rod. The film was baked in a 100℃ oven for 20 min, then removed and cut to a 3 cm × 3 cm size for testing. The band gap (E) was measured. g λ is an important and essential factor in evaluating photoelectric properties, and its value can be calculated from the initiation of a low-energy optical transition. 起始 E g =1240 / λ 起始 ). λ 起始 Taken from the intersection of the baseline and the tangent of the edge curve, such as Figure 3 As shown.

[0084] Color test:

[0085] A spectrophotometer was used to measure the color parameters of the polymer film in the neutral state and the oxidized state after applying voltage, in order to characterize the color change of the material during the electrochromic process.

[0086] Electrochemical spectroscopy test:

[0087] Electrochemical and spectroscopic data of polymer films were acquired using a fiber optic spectrometer with a voltage applied in increments of 0.1V from 0 to 1V.

[0088] Example 1

[0089] Step 1: Under a nitrogen atmosphere, add 5.7 mmol of MO1 monomer, 4 mmol of MO2 monomer, 0.3 mmol of MO5 monomer and 10 mmol of MO3 monomer to a dry and clean Schlenk tube, followed by the addition of catalysts, namely 226 mmol of K2CO3, 3 mmol of PivOH and 0.2 mmol of Pd(OAc)2.

[0090] Step 2: Evacuate the Shrek tube containing the monomer and catalyst for 15 minutes, then refill it with nitrogen. Repeat the evacuation and nitrogen replacement operation three times.

[0091] Step 3: Add the degassing solvent (see Table 3) to the Shrek tube to make the total concentration of all monomers in the degassing solvent reach 0.6 mol / L; heat the reaction solution to 160℃ and react for 6 hours.

[0092] Step 4: Add the reaction solution dropwise to 4 times its volume of methanol to precipitate the product. Filter to obtain crude polymer. Wash the crude polymer 8 times with deionized water, then wash it 3 times with methanol. Dry it in a high-temperature vacuum drying oven at 70°C for 24 hours to obtain polymer PO1.

[0093] The molecular weight (Mn) of polymer PO1 is 23.0 kDa, and the PDI is 1.8. 1 H NMR (400MHz, CDCl3): δ (ppm): 8.00-7.70 (d), 7.40-7.10 (m), 4.30-4.00 (m), 3.60-3.30 (m), 1.90-1.60 (m), 1.40-1.20 (m), 0.90-0.70 (t).

[0094] Figure 1 The cyclic voltammetry curve for P01 shows that the initial oxidation potential of P01 is approximately 0.32 V.

[0095] Figure 2 The electrochemical spectrum of PO1 shows that when a voltage is applied to the PO1 film from 0.0V to +1.0V, its overall absorption in the visible light region gradually decreases, while its absorption in the near-infrared region gradually increases. PO1 is visibly black to lighten gradually, eventually becoming nearly transparent.

[0096] Figure 3 The images show the UV-Vis absorption spectra of P01 in its neutral and oxidized states. They indicate that in the neutral state, P01 has an initial absorption wavelength of approximately 880 nm, an absorption peak at 689 nm, and another absorption peak at approximately 496 nm. In the oxidized state, P01 exhibits almost no absorption in the visible light region, appearing nearly transparent.

[0097] In Examples 2 to 23, the only differences from Example 1 are that the types and contents of the monomers, the types of solvents, the reaction temperature, and the reaction time are adjusted according to Table 3.

[0098] The molecular weight (Mn) of polymer PO2 is 13.2 kDa, and the PDI is 1.7. 1HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4 .00(m),4.00-3.70(t),3.60-3.30(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(t).

[0099] The molecular weight (Mn) of polymer PO3 is 16 kDa, and the PDI is 2.1. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.50-8.30 (d), 4.50-4.20 (m), 4.3-3.80 (m), 3.8-3.5 (m), 3.56-3.2 (m), 2.92-2.45 (m), 1.7-1.5 (m), 1.0-0.8 (m).

[0100] The molecular weight (Mn) of polymer PO4 is 16.6 kDa, and the PDI is 2.8. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(m).

[0101] The molecular weight (Mn) of polymer PO5 is 7.2 kDa, and the PDI is 1.3. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(m).

[0102] The molecular weight (Mn) of polymer PO6 is 6.9 kDa, and the PDI is 2.3. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(m).

[0103] The molecular weight (Mn) of polymer PO7 is 14.8 kDa, and the PDI is 2.3. 1HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.50-7.20 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(m),2.00-1.70(m),1.40-1.20(m),1.20-1.00(m).

[0104] The molecular weight (Mn) of polymer PO8 is 6.5 kDa, and the PDI is 1.5. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4.00(m),3.60-3.30(m),2.00-1.70(m),1.40-1.20(m),1.20-1.00(m).

[0105] The molecular weight (Mn) of polymer PO9 is 15.7 kDa, and the PDI is 1.2. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(m).

[0106] The molecular weight (Mn) of polymer P10 is 15.3 kDa, and the PDI is 1.6. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 2.80-2.50 (m), 1.90-1.60 (m), 1.40-1.20 (m), 0.90-0.70 (m).

[0107] The molecular weight (Mn) of polymer P11 is 15.2 kDa, and PDI = 1.5. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 6.00-5.80 (m), 4.30-4.00(m),3.80-3.50(m),3.60-3.30(m),2.00-1.80(m),1.90-1.60(m).

[0108] The molecular weight (Mn) of polymer P12 is 13.5 kDa, and the PDI is 1.3. 1HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(m).

[0109] The molecular weight (Mn) of polymer P13 is 13.1 kDa, and the PDI is 1.4. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.70-3.40(m),3.40-3.20(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(t).

[0110] The molecular weight (Mn) of polymer P14 is 17.3 kDa, and the PDI is 1.7. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.50-7.20 (m), 7.10-6.90 (m), 4.30-4.00 (m), 1.40-1.20 (m), 1.20-1.00 (d), 0.90-0.70 (t).

[0111] The molecular weight (Mn) of polymer P15 is 16.1 kDa, and the PDI is 2.5. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.30-7.00 (m), 4.30-4.00 (m), 3.60-3.30(m),2.40-2.20(s),1.90-1.60(m),1.40-1.20(m),0.90-0.70(t).

[0112] The molecular weight (Mn) of polymer P16 is 16.2 kDa, and the PDI is 3.0. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4.00(m),3.60-3.30(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(t).

[0113] The molecular weight (Mn) of polymer P17 is 6.9 kDa, and the PDI is 1.4. 1HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4 .00(m),4.00-3.70(t),3.60-3.30(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(t).

[0114] The molecular weight (Mn) of polymer P18 is 11.3 kDa, and the PDI is 1.3. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.50-7.20 (m), 7.10-6.90 (m), 4.30-4.00 (m), 1.40-1.20 (m), 1.20-1.00 (d), 0.90-0.70 (t).

[0115] The molecular weight (Mn) of polymer P19 is 17.0 kDa, and the PDI is 2.8. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4.00 (m), 4.00-3.70 (t), 1.40-1.20 (m), 0.90-0.70 (t).

[0116] The molecular weight (Mn) of polymer P20 is 19.0 kDa, and the PDI is 2.6. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4 .00(m),4.00-3.70(t),2.40-2.20(s),1.40-1.20(m),1.20-1.00(d),0.90-0.70(t).

[0117] The molecular weight (Mn) of polymer P21 is 9.2 kDa, and the PDI is 2.8. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.50-7.20 (m), 7.10-6.90 (m), 4.30-4.00(m),3.60-3.30(m),1.90-1.60(m),1.40-1.20(m),0.90-0.70(t).

[0118] The molecular weight (Mn) of polymer P22 is 11.5 kDa, and the PDI is 2.5. 1HNMR (400MHz, CDCl3): δ (ppm): 8.10-7.80 (d), 7.80-7.50 (d), 7.40-7.10 (m), 4.30-4.00 (m), 4.00-3.70 (t), 1.40-1.20 (m), 0.90-0.70 (t).

[0119] The molecular weight (Mn) of polymer P23 is 14.9 kDa, and the PDI is 1.6. 1 HNMR (400MHz, CDCl3): δ (ppm): 8.05-7.85 (d), 7.70-7.45 (d), 7.30-7.05 (m), 4.25-4.05(m),3.95-3.75(t),2.40-2.20(s),1.35-1.15(m),0.95-0.75(t).

[0120] Figure 4 The cyclic voltammetry curve for PO2 shows that the initial oxidation potential of PO2 is approximately 0.02 V.

[0121] Figure 5 The electrochemical spectrum of PO2 shows that when a voltage is applied to the PO2 film from 0.0V to +1.0V, its overall absorption in the visible light region gradually decreases, while its absorption in the near-infrared region gradually increases. This is visually observed as the black color gradually fades, eventually becoming nearly transparent.

[0122] Figure 6 The images show the UV-Vis absorption spectra of PO2 in its neutral and oxidized states. In the neutral state, the initial absorption wavelength is approximately 895 nm, with an absorption peak at 704 nm and another at approximately 500 nm. In the oxidized state, PO2 exhibits almost no absorption in the visible light region, appearing nearly transparent.

[0123] Figure 7 The UV-Vis absorption spectra of P01 and P02 in the neutral state show that different shades of black can be obtained by adjusting the types and proportions of monomers.

[0124] Table 1. Monomers required for the synthesis reaction of electrochromic materials

[0125] Table 2 Polymers of the Embodiments of the Invention

[0126] Table 3. Raw materials, reaction conditions, and yield of the embodiments of the present invention

[0127] Table 4 Performance of Polymer Films from Examples

[0128] As demonstrated by gel permeation chromatography and 1H NMR spectroscopy in Examples 1 to 23, polymers P01 to P23 were successfully synthesized and characterized in Examples 1 to 23. (Band gap (E)) g The photoelectric properties are an important factor in evaluating photoelectric performance. As can be seen from Examples 1 to 23, by selecting polymers within the scope of this application and adjusting the monomer ratio and the type and position of substituents on the monomers, a larger onset wavelength (λ) can be achieved. 起始 With a narrower optical band gap, electrochromic materials can more easily change color from black to transparent.

[0129] Onset oxidation potential (E) ox The value of the initial oxidation potential (OVP) typically affects the stability of electrochromic materials. A high OVP requires a large applied voltage after device fabrication, resulting in poor stability of the electrochromic device. As can be seen from Examples 1 to 23, by selecting polymers within the scope of this application, adjusting the monomer ratio and the type and position of substituents on the monomers, and controlling the OVP within the scope of this application, the electrochromic material can have a low OVP, indicating that the electrochromic device exhibits good stability.

[0130] Color standards are commonly used to evaluate color characteristic changes during electrochemical conversion processes. As can be seen from Examples 1 to 23, by selecting polymers within the scope of this application and adjusting the monomer ratio and the type and position of substituents on the monomers, the polymer film exhibits a black color in the neutral state, while in the oxidized state, the absorption in the visible light region weakens, and the polymer film appears nearly transparent. Furthermore, as can be seen from Examples 1 to 23, by controlling the monomer ratio in the preparation of the polymer, the hue of the polymer can be modulated to obtain different shades of black, demonstrating that the electrochromic material possesses excellent color modulation capabilities.

[0131] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An electrochromic material, characterized in that, The electrochromic material comprises a polymer of formula (I): ； Wherein, the number-average molecular weight of the polymer of formula (I) is 1,000 to 1,000,000; x, y, z, and w represent the molar percentages of A, B, C, and D in the polymer, respectively, where x ≥ 0, y > 0, z > 0, and w > 0. A, B, and C are selected from the following structural units: ； D is a conjugated spacer group, wherein D is selected from at least one of D1 to D15: ； ； ； ； Among them, R1, R2, R5, R6, R7, R8, R9, R 10 R 11 and R 12 Each is independently selected from hydrogen, C1-C 30 Alkyl, C3-C 30 Alkyl, C3-C 30 Alkynyl, C2-C 30 Alkyl carbonyl, C1-C 30 Alkoxy, C2-C 30 Alkoxycarbonyl, C1-C 30 Alkyl mercapto, C2-C 30 Alkylamino, C2-C 30 Alkylamide group, C2-C 30 Alkyl sulfonyl, C3-C 15 cycloalkyl, C1-C 30 Hydroxyalkyl, C3-C 30 Alkoxyalkyl, C6-C 14 Aryl, C7-C 30 Aryl group, C6-C 14 Aromatic amino, C7-C 30 Aryl (alkyl)amino, C6-C 14 arylalkoxy, C7-C 14 Aromatic amide group, C7-C 14 Alkyl ester group, C8-C 30 Aromatic oxyalkyl groups, C5-C7 saturated or unsaturated heterocyclic groups, C3-C 30 Polyether-based, C1-C 30 Fluoroalkyl groups and groups shown in formula (II), where R5 and R6 are not both represented as hydrogen; Wherein, the C5-C7 saturated heterocyclic groups are selected from tetrahydrofuran, tetrahydropyrrole, and tetrahydrothiophene; the C5-C7 unsaturated heterocyclic groups are selected from pyridyl, furanyl, and thiophene; wherein, R3 and R4 are each independently selected from hydrogen, fluorine, bromine, iodine, and C1-C 30 Alkyl, C1-C 30 Alkoxy, C6-C 14 Aryl; 。 2. The electrochromic material according to claim 1, characterized in that, The number-average molecular weight of the polymer of formula (I) is between 3,000 and 50,000.

3. The electrochromic material of claim 1, wherein, The polymer of formula (I) is any one of random copolymer, block copolymer or alternating copolymer.

4. The electrochromic material of claim 1, wherein, 0 ≤ x < 92.5%, 3% ≤ y < 100%, 0 < z < 93%, 0 < w ≤ 90%, preferably, 5% ≤ x ≤ 40%, 10% ≤ y ≤ 30%, 10% ≤ z ≤ 50%, 2% ≤ w ≤ 30%.

5. The electrochromic material of claim 1, wherein, R1and R2are each independently selected from the group consisting of C1-C 30 alkyl, C3-C 30 alkyl, C3-C 30 alkoxyalkyl.

6. The electrochromic material of claim 1, wherein, R3 and R4 are each independently selected from hydrogen, fluorine, and methyl.

7. The electrochromic material of claim 1, wherein, The polymer of formula (I) is selected from at least one of donor-donor fragment, donor-acceptor fragment, donor-conjugated spacer fragment, acceptor-conjugated spacer fragment, and conjugated spacer fragment, wherein the donor-donor fragment is selected from at least one of AA, AC, and CC; the donor-acceptor fragment is selected from at least one of BA and BC; and the donor-conjugated spacer fragment is selected from AD1, AD2, AD3, AD4, AD5, AD6, AD7, AD8, AD9, AD10, AD11, AD12, AD13, AD14, and A. The receptor-conjugated spacer fragment is selected from at least one of D15, CD1, CD2, CD3, CD4, CD5, CD6, CD7, CD8, CD9, CD10, CD11, CD12, CD13, CD14, and CD15; the acceptor-conjugated spacer fragment is selected from at least one of BD1, BD2, BD3, BD4, BD5, BD6, BD7, BD8, BD9, BD10, BD11, BD12, BD13, BD14, and BD15; the conjugated spacer fragment is selected from at least one of D10 and D11. ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； 。 8. The electrochromic material of claim 1, wherein, The polymer of formula (I) is selected from one of the structures shown in I-1 to I-37: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； Wherein, o, p, r, t, q, s, u, v, and m are the mole fractions of the corresponding structural segments, and each of o, p, r, t, q, s, u, v, and m independently satisfies: 0 ≤ o < 1, 0 ≤ p < 1, 0 ≤ r < 1, 0 ≤ t < 1, 0 ≤ q < 1, 0 ≤ s < 1, 0 ≤ u < 1, 0 ≤ v < 1, 0 ≤ m < 1. Preferably, 0.1 ≤ o ≤ 0.5, 0.1 ≤ p ≤ 0.5, 0.1 ≤ r ≤ 0.8, 0.05 ≤ t < 0.3, 0.05 ≤ q ≤ 0.5, 0.15 ≤ s ≤ 0.85, 0.1 ≤ u ≤ 0.8, 0.03 ≤ v ≤ 0.5, and 0.05 ≤ m ≤ 0.

8.

9. The electrochromic material of claim 1, wherein, The electrochromic material further includes a conductive material, which is selected from at least one of indium tin oxide, zinc aluminum oxide, fluorine-doped tin oxide, silver nanowires, graphene, carbon nanotubes, silver nanoparticle ink, and organic conductive polymers; wherein the organic conductive polymer is selected from at least one of PEDOT:PSS, polyaniline, and polypyrrole, preferably, the organic conductive polymer is selected from PEDOT:PSS.

10. The electrochromic material according to any one of claims 1 to 9, characterized in that, The initial absorption wavelength range in the neutral state is 840 nm to 1000 nm.

11. The electrochromic material according to any one of claims 1 to 9, characterized in that, The initial oxidation potential in the neutral state is E ox , 0 < E ox < 1.

5.

12. An electrochromic device, characterized in that, The electrochromic device comprises the electrochromic material according to any one of claims 1 to 11.

13. The electrochromic device of claim 12, wherein, The electrochromic devices described herein are used in automotive windows, anti-glare rearview mirrors, 3C products, building glass curtain walls, and eyeglasses.

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