Electrochromic medium composition and preparation method thereof and electrochromic device

Abstract

The present invention relates to the technical field of electrochromic materials, and in particular, to an electrochromic medium composition, a preparation method thereof, and an electrochromic device. The electrochromic medium composition comprises at least two anode electrochromic materials and one cathode electrochromic material, wherein the molar ratio of the anode electrochromic material to the cathode electrochromic material is 1:(0.5-1.5); one cathode electrochromic material comprises an electrochromic material capable of absorbing yellow light; at least two anode electrochromic materials comprise an electrochromic material capable of absorbing blue light and red light and an electrochromic material capable of absorbing green light, and the electrochromic material capable of absorbing green light is selected from the compounds shown in the following structural formula:. The electrochromic medium composition can achieve a neutral "gray" color state, further expanding the application of the electrochromic medium composition.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochromic materials, and in particular to an electrochromic medium composition and a preparation method thereof, and an electrochromic device. Background Art

[0002] Electrochromism is a phenomenon in which the optical properties of a material (reflectivity, transmittance, absorptivity, etc.) undergo stable and reversible color changes under the action of an external electric field, which manifests itself in appearance as reversible changes in color and transparency.

[0003] According to the principle of electrochromic reaction, electrochromic materials can be divided into anodic electrochromic materials and cathodic electrochromic materials. At present, cathodic electrochromic materials are mainly based on viologen and its derivatives, and anodic electrochromic materials are mainly based on compounds such as ferrocene, triphenylamine, phenazine, phenothiazine and their derivatives. Among them, the phenazine-viologen electrochromic system is the most commonly used red-blue electrochromic combination, but the electrochromic system has a good absorption effect on red and blue, and is not sensitive to green light, which also leads to the appearance of the devices prepared by this system being green for a long time. Therefore, when the electrochromic is used as a camera or other color-changing glass, the color of the observed object is distorted. Therefore, it is urgent to improve the phenazine-viologen electrochromic system so that the color of the electrochromic system can be closer to neutral colors such as gray.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide an electrochromic medium composition, a preparation method thereof and an electrochromic device. The electrochromic medium composition provided in the embodiment of the present invention can achieve a neutral "gray" color state, further expanding the application of the electrochromic medium composition.

[0006] The present invention is achieved in that:

[0007] In a first aspect, the present invention provides an electrochromic medium composition, which comprises at least two anode electrochromic materials and one cathode electrochromic material, wherein:

[0008] The molar ratio of the anode electrochromic material to the cathode electrochromic material is 1:(0.5-1.5);

[0009] The cathode electrochromic material includes an electrochromic material capable of absorbing yellow light;

[0010] At least two of the anode electrochromic materials include an electrochromic material capable of absorbing blue light and red light and an electrochromic material capable of absorbing green light, and the electrochromic material capable of absorbing green light is selected from the compounds represented by the following structural formula:

[0011] , where R1-R 28 are independently selected from any one of hydrogen, halogen, cyano, nitro, C1-C5 substituted or unsubstituted alkyl and OR', or R 12 and R 13 Connect into a ring, or R 26 and R 27 connected to form a ring; R′ is selected from any one of C1-C5 unsubstituted alkyl, C6-C10 aromatic or amino;

[0012] The molar ratio of the electrochromic material capable of absorbing blue light and red light to the electrochromic material capable of absorbing green light is 1:(0.5-2.5).

[0013] In a second aspect, the present invention provides a method for preparing the electrochromic medium composition described in the aforementioned embodiment, comprising: mixing at least two anode electrochromic materials and one cathode electrochromic material.

[0014] In a third aspect, the present invention provides an electrochromic device, which includes the electrochromic medium composition described in the aforementioned embodiment.

[0015] The present invention has the following beneficial effects: the embodiments of the present invention select electrochromic materials that can absorb yellow light, electrochromic materials that can absorb blue light and red light, and electrochromic materials that can absorb green light, and limit the molar ratio of the electrochromic materials that can absorb green light and the positive and negative electrochromic materials, so that the electrochromic medium composition achieves perfect adjustment of "neutral gray" and realizes full coverage of the electrochromic device in visible light. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0017] The embodiment of the present invention provides a new electrochromic medium composition, which includes at least two anode electrochromic materials and a cathode electrochromic material, wherein the molar ratio of the anode electrochromic material to the cathode electrochromic material is 1: (0.5-1.5); for example, the molar ratio is 1: 0.5, 1: 0.6, 1: 0.7, 1: 0.8, 1: 0.9, 1: 1, 1: 1.1, 1: 1.2, 1: 1.3, 1: 1.4 and 1: 1.5, etc., any value between 1: (0.5-1.5) or a range value between any two values. By adjusting the ratio of the cathode electrochromic material and the anode electrochromic material, the coloring depth of the electrochromic medium composition can be adjusted so that the electrochromic device achieves a neutral gray color effect.

[0018] Further, the concentration of the anode electrochromic material in the electrochromic medium composition is 1-100 mM, for example, 1Mm, 5 mM, 10 mM, 20 mM, 35 mM, 40 mM, 50 mM, 60 mM, 70 mM, 80 mM, 90 mM and 100 mM, any value between 1-100 mM or a range value between any two values, for example, preferably 10-50 mM, more preferably 30-35 mM. The specific concentration can be selected according to the contrast requirement in the visible light range.

[0019] The concentration of the cathode electrochromic material in the electrochromic medium composition is 1-100 mM, for example, 1Mm, 5 mM, 10 mM, 20 mM, 35 mM, 40 mM, 50 mM, 60 mM, 70 mM, 80 mM, 90 mM and 100 mM, any value between 1-100 mM or a range between any two values, for example, preferably 10-50 mM, more preferably 35-40 mM. The specific concentration can be selected according to the contrast requirement in the visible light range.

[0020] One type of cathode electrochromic material includes an electrochromic material that can absorb yellow light; for example, a viologen electrochromic material, such as a small molecule viologen derivative (specifically including but not limited to methyl viologen, ethyl viologen, n-propyl viologen, isopropyl viologen and benzyl viologen, etc.), a viologen functional conjugated polymer (for example, a suspended viologen material whose main chains are polyvinyl alcohol, polymethacrylate, polyethylene, and polystyrene, respectively).

[0021] At least two of the anode electrochromic materials include an electrochromic material capable of absorbing blue light and red light and an electrochromic material capable of absorbing green light, wherein the molar ratio of the electrochromic material capable of absorbing blue light and red light to the electrochromic material capable of absorbing green light is 1:(0.5-2.5), for example, any value between 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2 and 1:2.5, etc., or a range value between any two values. For example, it is preferably 1:(1.5-1.8). Further controlling the ratio of the two can enable the electrochromic device to achieve a neutral gray color effect.

[0022] The electrochromic material capable of absorbing blue light and red light is selected from phenazine electrochromic materials; for example, including but not limited to 5,10-dimethyl-5,10-dihydrophenazine, 5,10-diethyl-5,10-dihydrophenazine and 5,10-dibenzyl-5,10-dihydrophenazine.

[0023] The electrochromic material capable of absorbing green light is selected from the compounds represented by the following structural formula:

[0024] , where R1-R 28 are independently selected from any one of hydrogen, halogen, cyano, nitro, C1-C5 substituted or unsubstituted alkyl and OR', or R 12 and R 13 Connect into a ring, or R 26 and R 27 connected to form a ring; R′ is selected from any one of a C1-C5 unsubstituted alkyl group, a C6-C10 aromatic group or an amino group.

[0025] Specifically, the halogen includes any one of F, Cl, Br and I.

[0026] C1-C5 alkyl includes, but is not limited to, branched or straight chain alkyl such as methyl, ethyl, isopropyl, n-propyl, tert-butyl, n-butyl, isopentyl, n-pentyl and tert-pentyl. For example, preferably C1-C3 unsubstituted alkyl.

[0027] The substituents mentioned above refer to the substitution of one or more hydrogen atoms on any one carbon or multiple hydrogen atoms on multiple carbon atoms in the alkyl group by a group, and the group may be a halogen, a nitro group, a cyano group, an alkoxy group, or the like.

[0028] The C6-C10 aromatic group includes, but is not limited to, phenyl, benzyl or alkyl-substituted phenyl.

[0029] R 12 and R 13 connected to form a ring and the ring chelates an oxygen-containing heterocycle; or R 26 and R 27Connected to form a ring, and the ring chelates the oxygen-containing heterocycle.

[0030] At the same time, the embodiment of the present invention selects a specific compound that can absorb green light, so that its colored state is red, and forms a ternary system with an electrochromic material that can absorb yellow light and an electrochromic material that can absorb blue light and red light (such as a phenazine-viologen system) to achieve full wavelength coverage of visible light in the colored state. At the same time, by controlling the selection of R, the solubility of the above electrochromic material is controlled, so that the concentration of the electrochromic material that can absorb green light in the electrochromic medium composition is appropriate.

[0031] Specifically, the electrochromic material capable of absorbing green light is selected from any one of the compounds represented by the following structural formulas:

[0032] , , and .

[0033] Furthermore, the electrochromic medium composition provided in the embodiment of the present invention further includes at least one of a solvent, an ultraviolet absorption stabilizer, a thickener and a buffer solution. The solvent includes but is not limited to propylene carbonate solution (PC), γ-butyrolactone, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), etc. The thickener includes but is not limited to polymethyl methacrylate, polyvinyl pyrrolidone, etc. The amount of the above substances is within the existing commonly used range, and the embodiment of the present invention will not be described in detail.

[0034] In a second aspect, the present invention provides a method for preparing the electrochromic medium composition described in the aforementioned embodiment, comprising: mixing at least two anode electrochromic materials and one cathode electrochromic material. The specific mixing conditions such as mixing time and temperature are prior art and will not be described in detail in the embodiments of the present invention.

[0035] Specifically, the electrochromic material capable of absorbing green light is synthesized by Buchwald–Hartwig cross-coupling reaction, and the synthesis path is as follows:

[0036] ;For example,

[0037] ;

[0038] The input amounts of the reaction materials are as follows: 1 equivalent of compound a, 1 to 1.1 equivalents of compound b, 1 to 1.1 equivalents of compound c, 2.0 to 2.5 equivalents of sodium alcoholate (e.g. sodium tert-butoxide (t-BuOK)), 0.02 to 0.05 equivalents of alkyl phosphine (e.g. tri-tert-butylphosphine ((t-Bu)3P)), 0.005 to 0.02 equivalents of palladium catalyst (e.g. palladium acetate (Pd(OAc)2)); the reaction temperature is 100 to 120°C.

[0039] In a third aspect, the present invention provides an electrochromic device, which includes the electrochromic medium composition described in the aforementioned embodiment.

[0040] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0041] Synthesis example 1

[0042] This synthesis example provides a red electrochromic material (Compound 1) that can absorb green light, and its structural formula is as follows:

[0043] .

[0044] The synthesis process of compound 1 is as follows: 3.82 g 4,4'-dimethoxydiphenylamine, 2.50 g 4,4'-dibromobiphenyl, 1.92 g sodium tert-butoxide, 72 mg palladium acetate, 52 mg tri-tert-butylphosphine, and 20 mL anhydrous toluene were added to a two-necked round-bottom flask, heated to reflux under N2 atmosphere, and the reaction progress was monitored by thin layer chromatography. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed 3 times with 100 mL saturated NaCl solution. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / dichloromethane = 2 / 1) to obtain 4.28 g of compound 1 (yield 88%).

[0045] Characterization data: 1 H NMR (500 MHz, DMSO-d6): δ 7.38 (d, J = 8.3 Hz, 4H), 7.01(d, J = 8.3 Hz, 8H), 6.89 (d, J = 8.3 Hz, 8H), 6.80 (d, J = 8.3 Hz, 4H), 3.73(s, 12H).

[0046] Synthesis example 2

[0047] This synthesis example provides a red electrochromic material (Compound 2) that can absorb green light, and its structural formula is as follows:

[0048] .

[0049] The synthesis process of compound 2 is as follows: 3.82 g 3,3'-dimethoxydiphenylamine, 2.50 g 4,4'-dibromobiphenyl, 1.92 g sodium tert-butoxide, 72 mg palladium acetate, 52 mg tri-tert-butylphosphine, 20 mL anhydrous toluene were added to a two-necked round-bottom flask, heated to reflux under N2 atmosphere, and the reaction progress was monitored by thin layer chromatography. When the raw materials reacted completely, they were cooled to room temperature, the organic phase was washed 3 times with 100 mL saturated NaCl solution, and the organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / dichloromethane = 2 / 1) to obtain 4.28 g of compound 2 (yield 82%).

[0050] Characterization data: 1 H NMR (500 MHz, CDCl3): δ 7.48 (d, J = 8.3 Hz, 4H), 7.16-7.19 (m, 8H), 6.73-6.74 (m, 8H), 6.61 (d, J = 8.3 Hz, 4H), 3.75 (s, 12H).

[0051] Synthesis example 3

[0052] This synthesis example provides a red electrochromic material (Compound 3) that can absorb green light, and its structural formula is as follows:

[0053] .

[0054] The synthesis process of compound 3 is as follows:

[0055] A mixture of 9.41 g of phenol, 3.38 g of 2,7-dibromo-9-fluorenone and 2.6 ml of methanesulfonic acid was heated at 150°C for 24 hours. After the reaction was cooled to room temperature, 100 ml of methanol was slowly added to the mixture, and the white precipitate was filtered and washed with a large amount of methanol to obtain 4.42 g of intermediate 1 (yield 90%).

[0056] The structural formula of intermediate 1 is as follows: .

[0057] Characterization data of intermediate 1: 1 H NMR (500 MHz, (CD 3)2 CO, 298 K, δ): 7.96 (d, J =10 Hz, 2H), 7.63 (d, J = 10 Hz, 2H), 7.30~7.28 (m, 6H), 6.91~6.87 (m, 2H), 6.41 (d, J = 10 Hz, 2H).

[0058] 0.76 g 4,4'-dimethoxydiphenylamine, 0.74 g 2,7-dibromospiro[fluorene-9,9'-oxanthene], and 0.92 g NaOtBu were added to 30 mL anhydrous toluene. After bubbling with nitrogen several times, 12 mg P(t-Bu)3 and 14 mg Pd(OAc)2 were added and refluxed overnight. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed with 100 mL saturated NaCl solution for 3 times. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / ethyl acetate = 1 / 1) to obtain 1.0 g of compound 3 (yield 85%).

[0059] Characterization data of compound 3: 1 H NMR (500 MHz, DMSO-d6, 298 K, δ): 7.58 (d, J = 10Hz, 2H), 7.24 (t, J = 5 Hz, 2H), 7.13 (d, J = 10 Hz, 2H), 6.95 (t, J = 10 Hz, 2H), 6.86~6.72 (m, 18H), 6.48 (d, J = 10 Hz, 4H), 3.68 (s, 12H).

[0060] Synthesis example 4

[0061] This synthesis example provides a red electrochromic material (Compound 4) that can absorb green light, and its structural formula is as follows:

[0062] .

[0063] The synthesis process of compound 4 is as follows:

[0064] A mixture of 3.66 g 2,7-dibromophenanthrenequinone, 2 ml ethylene glycol, and 2.6 ml methanesulfonic acid was refluxed in 50 mL methanol for 24 hours. After the reaction was cooled to room temperature, the solvent was evaporated to dryness, washed three times with 100 mL saturated NaCl solution, and filtered to obtain a crude product, which was then purified by column chromatography (mobile phase: petroleum ether / ethyl acetate = 1 / 1) to obtain 3.8 g intermediate 2 (yield 84%).

[0065] The structural formula of intermediate 2 is as follows: .

[0066] Characterization data of intermediate 2: 1H NMR (400 MHz, CDCl3) δ: 7.88 (d, 2H, J = 2.0 Hz), 7.71 (d, 2H, J = 8.4 Hz), 7.59 (dd, 2H, J1 = 8.4 Hz, J2 = 2.0 Hz), 4.22 (bs,4H), 3.67 (bs, 4H).

[0067] 0.76 g 4,4'-dimethoxydiphenylamine, 0.70 g intermediate 2, and 0.92 g NaOtBu were added to 30 mL anhydrous toluene. After bubbling with nitrogen several times, 12 mg P(t-Bu)3 and 14 mg Pd(OAc)2 were added and refluxed overnight. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed with 100 mL saturated NaCl solution for 3 times. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / ethyl acetate = 1 / 1) to obtain 0.97 g compound 4 (yield 84%).

[0068] Characterization data of compound 4: 1 H NMR (400 MHz, CDCl3) δ: 7.88 (d, 2H, J = 2.0 Hz), 7.71 (d, 2H, J = 8.4 Hz), 7.59 (dd, 2H, J1 = 8.4 Hz, J2 = 2.0 Hz), 4.22 (bs,4H), 3.67 (bs, 4H).

[0069] Synthesis example 5

[0070] This synthesis example provides a red electrochromic material (Compound 5) that can absorb green light, and its structural formula is as follows:

[0071] .

[0072] The synthesis process of compound 5 is as follows:

[0073] 0.65 g 4,4'-dimethyldiphenylamine, 0.57 g 4,4'-dibromo-2,2'-difluoro-1,1'-biphenyl, and 0.92 g NaOtBu were added to 30 mL anhydrous toluene. After bubbling with nitrogen several times, 12 mg P(t-Bu)3 and 14 mg Pd(OAc)2 were added and refluxed overnight. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed with 100 mL saturated NaCl solution for 3 times. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / dichloromethane = 1 / 1) to obtain 0.66 g of compound 5 (yield 69%).

[0074] Characterization data of compound 5: 1 H NMR (400 MHz, DMSO-d6) δ: 7.71 (m, 2H), 7.47 (s, 2H), 7.15-7.10 (m, 18H), 2.32 (s, 12H).

[0075] Synthesis example 6

[0076] This synthesis example provides a red electrochromic material (Compound 6) that can absorb green light, and its structural formula is as follows:

[0077] .

[0078] The synthesis process of compound 6 is as follows:

[0079] 0.68 g 4,4'-difluorodiphenylamine, 0.56 g 4,4'-dibromo-2,2'-dimethyl-1,1'-biphenyl, and 0.92 g NaOtBu were added to 30 mL anhydrous toluene. After bubbling with nitrogen several times, 12 mg P(t-Bu)3 and 14 mg Pd(OAc)2 were added and refluxed overnight. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed with 100 mL saturated NaCl solution for 3 times. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / dichloromethane = 1 / 1) to obtain 0.59 g of compound 6 (yield 61%).

[0080] Characterization data of compound 6: 1 H NMR (400 MHz, DMSO-d6) δ: 7.68 (d, 2H, J=7.0 Hz), 7.44 (s, 2H), 7.27 (d, 2H, J=6.8 Hz), 7.18-7.05 (m, 16H), 2.57 (s, 6H).

[0081] Test Example 1

[0082] Absorption wavelength test: The maximum absorption wavelength of compound 1 in the colored state was measured to be 460 nm using a spectroelectrochemical device, the maximum absorption wavelength of compound 2 in the colored state was measured to be 520 nm, the maximum absorption wavelength of compound 3 in the colored state was measured to be 518 nm, and the maximum absorption wavelength of compound 4 in the colored state was measured to be 516 nm. The maximum absorption wavelength of compound 5 in the colored state was measured to be 498 nm. The maximum absorption wavelength of compound 6 in the colored state was measured to be 493 nm.

[0083] According to the above absorption wavelength test results, the maximum absorption of the colored state of compounds 1-6 provided in the embodiments of the present invention is between 445 and 520 nm, among which compounds 2, 3 and 4 have a higher sensitivity to green light (around 520 nm).

[0084] Example 1

[0085] The embodiment of the present invention provides an electrochromic medium composition (referred to as electrochromic medium 1), the solvent used in the composition is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0086]

[0087] Example 2

[0088] The embodiment of the present invention provides an electrochromic medium composition (referred to as electrochromic medium 2), the solvent used in which is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0089]

[0090] Example 3

[0091] The embodiment of the present invention provides an electrochromic medium composition (referred to as electrochromic medium 3), the solvent used in which is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0092]

[0093] Example 4

[0094] The embodiment of the present invention provides an electrochromic medium composition (referred to as electrochromic medium 4), the solvent used in which is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0095]

[0096] Example 5

[0097] The present embodiment provides three electrochromic medium compositions (respectively referred to as electrochromic medium 5a, 5b and 5c), wherein the solvent used is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0098]

[0099] Example 6

[0100] The present embodiment provides three electrochromic medium compositions (respectively referred to as electrochromic medium 6a, 6b and 6c), wherein the solvent used is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0101]

[0102] Example 7

[0103] The present invention provides three electrochromic medium compositions (respectively referred to as electrochromic medium 7a, 7b and 7c), wherein the solvent used is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0104]

[0105] Example 8

[0106] The present invention provides three electrochromic medium compositions (respectively referred to as electrochromic medium 8a, 8b and 8c), wherein the solvent used is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0107]

[0108] Example 9

[0109] The present embodiment provides three electrochromic medium compositions (respectively referred to as electrochromic medium 9a, 9b and 9c), wherein the solvent used is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0110]

[0111] Comparative Example 1

[0112] This comparative example provides an electrochromic medium composition (referred to as electrochromic medium A), the solvent used in which is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0113]

[0114] Comparative Example 2

[0115] This comparative example provides an electrochromic medium composition (referred to as electrochromic medium B), the solvent used in which is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0116]

[0117] The structural formula of compound 7 is shown below:

[0118] .

[0119] The process of preparing compound 7 is as follows:

[0120] 0.76 g 4,4'-dimethoxydiphenylamine, 0.6 g 4,4'-dibromo-[1,1'-biphenyl]-2,2'-dicarbonitrile, and 0.92 g NaOtBu were added to 30 mL anhydrous toluene. After bubbling with nitrogen several times, 12 mg P(t-Bu)3 and 14 mg Pd(OAc)2 were added and refluxed overnight. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed with 100 mL saturated NaCl solution for 3 times. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / dichloromethane = 1 / 2) to obtain 0.48 g of compound 7 (yield 44%).

[0121] The characterization data of compound 7 are as follows: 1 H NMR (400 MHz, DMSO-d6) δ: 7.91 (d, 2H, J=6.4Hz), 7.65-7.60 (m, 4H), 7.18 (d, 8H, J=6.8 Hz), 6.79 (d, 8H, J=6.2 Hz), 3.81(s, 12H)

[0122] The maximum absorption wavelength of comparative compound 1 in the colored state was measured to be 458 nm, and the absorption of green light was very limited, which was due to the introduction of a strong electron-withdrawing cyano group.

[0123] Comparative Example 3

[0124] This comparative example provides an electrochromic medium composition (referred to as electrochromic medium C), the solvent used in which is propylene carbonate solution (PC). Specifically, the electrochromic material composition is shown in the following table:

[0125]

[0126] The structural formula of compound 8 is shown below:

[0127]

[0128] The preparation steps of compound 8 are as follows:

[0129] 0.76 g 4,4'-dimethoxydiphenylamine, 0.74 g 4,4'-dibromo-2,2'-bis(trifluoromethyl)-1,1'-biphenyl, and 0.92 g NaOtBu were added to 30 mL anhydrous toluene. After bubbling with nitrogen several times, 12 mg P(t-Bu)3 and 14 mg Pd(OAc)2 were added and refluxed overnight. When the raw materials reacted completely, they were cooled to room temperature, and the organic phase was washed with 100 mL saturated NaCl solution for 3 times. The organic phase was distilled under reduced pressure to obtain a crude product, which was purified by column chromatography (mobile phase: petroleum ether / dichloromethane = 1 / 2) to obtain 0.5 g of compound 8 (yield 41%).

[0130] The characterization data of compound 8 are as follows: 1 H NMR (400 MHz, DMSO-d6) δ: 7.75 (s, 2H), 7.67-7.64 (m, 2H), 7.37 (d, 2H, J=6.8 Hz), 7.18 (d, 8H, J=6.3 Hz), 6.79 (d, 8H, J=6.6 Hz), 3.88 (s, 12H)

[0131] The maximum absorption wavelength of comparative compound 2 in the colored state was measured to be 454 nm, and the absorption of green light was very limited, which was due to the introduction of a strongly electron-withdrawing trifluoromethyl group.

[0132] Test Example 2

[0133] The electrochromic medium compositions provided in the above examples and comparative examples were tested, specifically, the L, a and b values ​​at a voltage of 1.2 V. The results are shown in the following table:

[0134]

[0135] It should be noted that the L* value, a* value, and b* value in the Lab color space represent the brightness, red-green color, and yellow-blue color, respectively. The larger the L* value, the higher the brightness of the color. When a*>0, it means that the color is red, and the larger the a* value, the more red the color is; when a*<0, it means that the color is green, and the smaller the a* value, the more green the color is. When b*>0, it means that the color is yellow, and the larger the b* value, the more yellow the color is; when b*<0, it means that the color is blue, and the smaller the b* value, the more blue the color is.

[0136] As can be seen from the above table, the a* value in the system composed of 5,10-dimethyl-5,10-dihydrophenazine and ethyl viologen is relatively negative, and its colored state is green. When the compounds 1-4 provided in the embodiments of the present invention are introduced, the a* value is greatly regulated, among which the combination of compounds 1 and 3 (Examples 5a-5c) has the best regulation of the a* value of the system (close to 0), and the colored state is close to "neutral gray". Due to the introduction of strong electron-withdrawing groups, the coloring state of comparative compounds 1 and comparative compounds 2 is orange, which deviates from "neutral gray". This reflects the advantages of the electrochromic medium composition provided in the embodiments of the present invention. By introducing a red anode electrochromic material that can absorb green light, the device coloring state can reach neutral gray.

[0137] Application Examples

[0138] Two pieces of 40*40*0.4mm ITO-coated glass were glued together at offset points, and the thickness of the device box was 125 microns. The above materials were mixed into a solution and filled into the prepared electrochromic device by vacuum filling. A voltage was applied to both ends, and the transmittance data of the electrochromic medium composition of comparative example 1 and the electrochromic medium composition of embodiment 3 in the 550 nm band under 0~1.2 V were measured, as shown in the following table:

[0139]

[0140] As can be seen from the above table, the electrochromic medium composition of comparative example 1 (without red anode material) has a very poor absorption capacity for light emitted at 550 nm in the colored state. After the introduction of the red anode material compound 3, the transmittance is significantly lower, indicating that the addition of compound 3 provided in the embodiment of the present invention enhances the effective absorption of green light by the device. It can be seen that by introducing the red anode material capable of absorbing green light provided in the embodiment of the present invention into the dimethoxazine-viologen system, the perfect adjustment of "neutral gray" is achieved, and the full coverage of the electrochromic device in visible light is achieved.

[0141] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electrochromic medium composition, characterized in that: It includes two anode electrochromic materials and one cathode electrochromic material, wherein: The molar ratio of the anode electrochromic material to the cathode electrochromic material is 1:(1-1.5); The cathode electrochromic material is selected from ethyl viologen; The two anode electrochromic materials are selected from the electrochromic material 5,10-dimethyl-5,10-dihydrophenazine that can absorb blue light and red light and the electrochromic material that can absorb green light; The electrochromic material capable of absorbing green light is selected from any one of the following: (1) and combination; the molar ratio of the two is 1:1, 1:3 or 3:1; （2） ； （3） ； The molar ratio of the electrochromic material capable of absorbing blue light and red light to the electrochromic material capable of absorbing green light is 1:(0.5-2.5).

2. The electrochromic medium composition according to claim 1, characterized in that: The concentration of the anode electrochromic material in the electrochromic medium composition is 1-100 mM, and the concentration of the cathode electrochromic material in the electrochromic medium composition is 1-100 mM.

3. A method for preparing the electrochromic medium composition according to claim 1, characterized in that: include: Two anodic electrochromic materials and one cathodic electrochromic material are mixed.

4. The preparation method according to claim 3, characterized in that: The electrochromic material capable of absorbing green light is synthesized according to the following synthesis route: ； The input amount of the reaction materials is as follows: 1 equivalent of compound a, 1-1.1 equivalents of compound b, 1-1.1 equivalents of compound c, 2.0-2.5 equivalents of sodium alcoholate material, 0.02-0.05 equivalents of alkyl phosphine, and 0.005-0.02 equivalents of palladium catalyst; The reaction temperature is 100~120℃, R1-R 28 The corresponding groups are as described above.

5. An electrochromic device, characterized in that: The invention comprises the electrochromic medium composition according to claim 1.

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