阅读说明：本技术 用于电致变色器件的电解液以及相应的电致变色器件 (Electrolyte for electrochromic device and corresponding electrochromic device ) 是由 李维军 蒯羽 张�诚 付海长 展望 于 2020-12-23 设计创作，主要内容包括：本发明公开了用于电致变色器件的电解液以及相应的电致变色器件。所述的电解液为液态电解液或固体电解液,所述液体电解液包括至少一种高标准电极电势金属离子,所述金属离子的标准电极电势要高于电致变色器件采用的导电聚合物的标准电极电势并且其不与电解质发生化学反应。本发明提供了利用所述电解液制备得到的电致变色器件。本发明所述的液体电解液和固体电解液能够大幅减小电致变色器件电压的同时大幅提升其响应速度。定。(The invention discloses an electrolyte for an electrochromic device and a corresponding electrochromic device. The electrolyte is a liquid electrolyte or a solid electrolyte, the liquid electrolyte comprises at least one metal ion with high standard electrode potential, the standard electrode potential of the metal ion is higher than the standard electrode potential of a conductive polymer adopted by the electrochromic device, and the metal ion does not react with the electrolyte chemically. The invention provides an electrochromic device prepared by using the electrolyte. The liquid electrolyte and the solid electrolyte can greatly reduce the voltage of the electrochromic device and simultaneously greatly improve the response speed of the electrochromic device. And (4) determining.)

1. An electrolyte for an electrochromic device, the electrolyte is a liquid electrolyte, the liquid electrolyte comprises an electrolyte and a solvent, and the electrochromic device is characterized in that: the liquid electrolyte further comprises at least one high standard electrode potential metal ion having a standard electrode potential higher than that of a conductive polymer used in the electrochromic device and which does not chemically react with the electrolyte.

2. The electrolyte for electrochromic devices according to claim 1, wherein: the high standard electrode potential metal ion is Fe³⁺Said Fe³⁺The concentration of the solvent is 0.05-0.1mol/L, and the solvent is acetonitrile or ethanol.

3. The electrolyte for electrochromic devices according to claim 2, wherein: said Fe³⁺With FeCl₃Is added in the form of (1).

4. The electrolyte for electrochromic devices according to claim 2, wherein: the solvent is acetonitrile.

5. The electrolyte for electrochromic devices according to any of claims 1 to 4, wherein: in the liquid electrolyte, the concentration of the electrolyte is 0.05-0.1 mol/L.

6. The electrolyte for electrochromic devices according to any of claims 1 to 4, wherein: the electrolyte is tetrabutylammonium perchlorate, and the concentration of the electrolyte is 0.05-0.1 mol/L.

7. An electrolyte for an electrochromic device, wherein the electrolyte is a solid electrolyte, and the solid electrolyte comprises a polymer matrix, a plasticizer and an electrolyte, and is characterized in that: the solid electrolyte further comprises at least one high standard electrode potential metal ion having a standard electrode potential higher than that of a conductive polymer used for the electrochromic device and which does not chemically react with the electrolyte.

8. The electrolyte for electrochromic devices according to any of claims 1 to 4, wherein: the high standard electrode potential metal ion is Fe³⁺And with FeCl₃In the form of FeCl in the solid electrolyte₃The mass content of (A) is 0.5-2%.

9. The electrolyte for electrochromic devices according to any of claims 1 to 4, wherein: the electrolyte is tetrabutylammonium perchlorate, and the electrolyte content in the solid electrolyte is 1-5%.

10. An electrochromic device prepared using the electrolyte according to claim 1 or 7.

Technical Field

The present invention relates to an electrolyte for an electrochromic device and a corresponding electrochromic device.

Background

The conductive polymer is discovered by Japanese scientist white-English tree in the 70 th century, and through the development of the recent 50 years, the conductive polymer has been deeply researched in a plurality of fields of chemistry, physics, biology, electronics and the like, and some technical applications even realize daily production.

The research and application of conductive polymers in the field of color change mainly focuses on the direction of electrochromism. Electrochromic is a new research field, and has the following advantages: the suitable working temperature range is large; the energy consumption is low, and the matching with an integrated circuit is easy; the color adjustable range is wide and continuous color change can be realized; has memory function, and the color change can be maintained in open circuit state. Compared with inorganic materials, the conductive polymer as the electrochromic material has the advantages of wider color gamut, higher processability and the like.

The technology of the invention can further reduce the applied color-changing voltage required by the electrochromic device, further improve the response speed, save more energy and realize green life.

Disclosure of Invention

The invention aims to provide an electrolyte applied to an electrochromic device so as to further reduce the color-changing voltage of the electrochromic device and improve the response speed of the electrochromic device.

The second problem to be solved by the present invention is to provide an electrochromic device prepared from the electrolyte.

The invention adopts the following technical scheme for solving the technical problems:

in a first aspect, the present invention provides an electrolyte for an electrochromic device, wherein the electrolyte is a liquid electrolyte comprising an electrolyte and a solvent, and further comprises at least one high standard electrode potential metal ion, wherein the standard electrode potential of the metal ion is higher than the standard electrode potential of a conductive polymer used in the electrochromic device and the metal ion does not chemically react with the electrolyte.

In the liquid electrolyte, the concentration of the electrolyte is conventional, and is generally 0.05-0.1 mol/L; the higher the concentration of the metal ions at the high standard electrode potential is, the better theoretically, but considering the application thereof in an electrochromic device, it is preferable that the color change of the electrolyte caused by the addition amount thereof does not affect the electrochromic performance of the device.

Preferably, the metal ion with high standard electrode potential is Fe³⁺Said Fe³⁺The concentration of the solvent is 0.05-0.1mol/L, and the solvent is acetonitrile or ethanol.

As a further preference, said Fe³⁺With FeCl₃Is added in the form of (1).

Further preferably, the solvent is acetonitrile.

Further preferably, the electrolyte is tetrabutylammonium perchlorate (TBAP) with a concentration of 0.05 to 0.1 mol/L.

In a second aspect, the present invention provides an electrolyte for an electrochromic device, the electrolyte being a solid electrolyte comprising a polymer matrix, a plasticizer and an electrolyte, and further comprising at least one metal ion with a high standard electrode potential, the metal ion having a standard electrode potential higher than the standard electrode potential of a conductive polymer used in the electrochromic device and being chemically non-reactive with the electrolyte.

In the solid electrolyte, the polymer matrix and the plasticizer are selected and contained according to the content of the polymer matrix (such as polymethyl methacrylate, polyvinylidene fluoride, poly (vinylidene fluoride-hexachloropropene) and the like) and the plasticizer (such as propylene carbonate, polyethylene glycol and the like) which are commonly used in the conventional solid electrolyte and the content of corresponding components. The electrolyte is selected from the liquid electrolyte, does not react with high-standard electrode potential ions, has no special requirement on the electrolyte content, and can be prepared by adopting the conventional content. The higher the content of the high-standard electrode potential ions is, the better the content is theoretically, but considering the application of the high-standard electrode potential ions in an electrochromic device, the color change of the electrolyte caused by the addition amount of the high-standard electrode potential ions does not influence the electrochromic performance of the device.

Preferably, the metal ion with high standard electrode potential is Fe³⁺And with FeCl₃In the form of FeCl in the solid electrolyte₃The content of (b) is 0.5 to 2% by mass, more preferably 1% by mass.

More preferably, the electrolyte is tetrabutylammonium perchlorate (TBAP), and the electrolyte content in the solid electrolyte is 1-5%.

Preferably, the polymer matrix is PMMA (polymethyl methacrylate), and the plasticizer is PC (propylene carbonate).

The solid electrolyte is specifically recommended to be prepared by the following method: adding a polymer matrix and a plasticizer into a reaction container, adding the liquid electrolyte after full swelling, and removing the solvent by using a rotary evaporator after uniform ultrasonic treatment to obtain the solid electrolyte.

When the polymer matrix is PMMA and the plasticizer is PC, the material ratio of PMMA to PC is preferably 2-4 g: 5-10ml, mixing PMMA and PC, swelling for 3-5 days at 60-80 ℃, and then adding liquid electrolyte. Further preferably, the charge ratio of PMMA to PC is 2.1 g: 5 ml. Further preferably, the swelling temperature is 60 ℃ and the swelling time is 5 days.

Preferably, the solvent in the liquid electrolyte is acetonitrile or ethanol, and most preferably acetonitrile.

Further preferably, in the liquid electrolyte, the Fe is present³⁺Is 0.05 to 0.1mol/L, and the concentration of the tetrabutylammonium perchlorate (TBAP) is 0.05 to 0.1 mol/L.

In a third aspect, the invention provides an electrochromic device prepared by using the electrolyte.

The liquid electrolyte or the solid electrolyte can be used for preparing an electrochromic device through conventional operation, and specifically comprises the following steps:

(1) preparation of conductive polymer solution: preparing 1-10mg/ml of conductive polymer solution;

(2) preparation of conductive polymer film: coating the conductive polymer solution prepared in the step (1) on the surface of the ITO glass by using a spin coating method to form a conductive polymer film;

(3) preparing a liquid or solid electrolyte;

(4) preparing an electrochromic device: and (3) taking the ITO glass coated with the conductive polymer film and prepared in the step (2) as a working electrode, taking blank ITO glass as a counter electrode, taking the electrolyte prepared in the step (3) as a device electrolyte, and taking 3M glue as a packaging means to assemble the electrochromic device, so as to obtain the electrochromic device.

Preferably, the conductive polymer in step (1) is ProDOT, and the solvent is dichloromethane or chloroform, and more preferably, the solvent is chloroform. It is further preferable that the concentration of the electroconductive polymer solution in the step (1) is 5 mg/ml.

Preferably, the step (2) is specifically performed as follows: placing the ITO glass on a spin coater, uniformly dripping the prepared conducting polymer solution in the step (1) on the surface of the ITO glass by using a dropper, starting the spin coater at the rotating speed of 500-2000 r/min for 30-90 s, and finishing the preparation of the conducting polymer film after stopping.

Compared with the prior art, the invention has the following beneficial effects:

(1) the liquid electrolyte and the solid electrolyte can greatly reduce the voltage of the electrochromic device and simultaneously greatly improve the response speed of the electrochromic device, further save energy and create green life.

(2) The preparation method of the electrolyte is simple and easy to implement, and does not need harsh conditions.

(3) The composite film obtained by the spin coating film forming method adopted by the invention is uniform and stable when the electrochromic device is prepared.

Drawings

FIG. 1 shows electrochromic devices Device I and Device II prepared in example 1 and comparative example 1. Under normal light, Device i is in a yellowish transparent state and Device ii is in a magenta state.

FIG. 2 is a graph showing the UV absorption of the electrochromic devices Device I and Device II according to the voltage change, wherein a) corresponds to Device I and b) corresponds to Device II, obtained in example 1 and comparative example 1.

FIG. 3 is a graph showing contrast and response time at 570nm for the electrochromic devices Device I and Device II prepared in example 1 and comparative example 1, where the upper part corresponds to Device I and the lower part corresponds to Device II.

FIG. 4 is a graph showing contrast and response time at 570nm for the electrochromic devices Device III and Device II prepared in example 2 and comparative example 1, where the upper side corresponds to Device II and the lower side corresponds to Device III.

FIG. 5 is a graph showing contrast and response time at 570nm for the electrochromic devices Device IV and Device II prepared in example 3 and comparative example 1, where the upper part corresponds to Device II and the lower part corresponds to Device IV.

Fig. 6 is a synthesis scheme of the conducting polymer ProDOT.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.

The conductive polymer ProDOT used in the embodiment of the invention is synthesized by itself, the synthetic route is shown in figure 6, and the synthetic steps are referenced in the literature:

1.M.D.Keersmaecker and J.R.Reynolds；ACS Appl.Mater.Interfaces 2019,11,47131-47142.

2.J.A.Kerszulis,C.M.Amb,A.L.Dyer and J.R.Reynolds；Macromolecules 2014,47,5462-5469.

3.G.S.Collier,J.R.Reynolds；ACS Macro Lett.2019,8,931-936.

chloroform, acetonitrile, PC, FeCl used in the examples₃The raw materials required for PMMA and ProDOT synthesis are available from reagent companies such as Aladdin, carbofuran, Biddo medicine, etc.

Example 1

(1) Preparation of conductive polymer (ProDOT) solution: a chloroform solution of the conductive polymer (5 mg/ml) was prepared in a 10ml volumetric flask.

(2) Preparation of conductive polymer film: preparing the conductive polymer film by using a spin coating method, firstly placing the ITO glass on a spin coater, then uniformly dripping the prepared conductive polymer solution in the step (1) on the surface of the ITO glass by using a dropper, starting the spin coater at the rotating speed of 1000r/min for 60s, and stopping to prepare the conductive polymer film.

(3) ComprisesWith Fe³⁺Preparing the liquid electrolyte: the total concentration of 0.1mol/LFeCl was prepared in a 10ml volumetric flask₃And TBAP in a mixed acetonitrile solution, in which FeCl₃The concentration is 0.05mol/L, and the TBAP concentration is 0.05 mol/L.

(4) Preparing an electrochromic device: (2) the ITO glass spin-coated with the conductive polymer film prepared in the step (3) is used as a working electrode, the blank ITO glass is used as a counter electrode, the electrolyte prepared in the step (3) is used as device electrolyte, and 3M glue is used as a packaging means for assembling the electrochromic device.

The resulting Device is referred to as Device i, as shown in fig. 1.

Comparative example 1

(1) Preparation of conductive polymer (ProDOT) solution: a5 mg/ml solution of the conductive polymer chloroform was prepared in a 10ml volumetric flask.

(2) Preparation of conductive polymer film: preparing the conductive polymer film by using a spin coating method, firstly placing the ITO glass on a spin coater, then uniformly dripping the prepared conductive polymer solution in the step (1) on the surface of the ITO glass by using a dropper, starting the spin coater at the rotating speed of 1000r/min for 60s, and stopping to prepare the conductive polymer film.

(3) Preparing a TBAP-containing liquid electrolyte: a0.1 mol/LTBAP solution in acetonitrile was prepared in a 10ml volumetric flask.

(4) Preparing an electrochromic device: (2) the ITO glass spin-coated with the conductive polymer film prepared in the step (3) is used as a working electrode, the blank ITO glass is used as a counter electrode, the electrolyte prepared in the step (3) is used as device electrolyte, and 3M glue is used as a packaging means for assembling the electrochromic device.

The resulting Device was designated Device ii as described in fig. 1.

The devices Device I and Device II obtained in example 1 and comparative example 1 were subjected to UV absorption tests at different voltages, as shown in FIG. 2, and the absorption values at about 450-650nm varied at different voltages, indicating that electrochromic phenomenon existed and the color change voltage of Device I was significantly lower than that of Device II.

The contrast and response time tests were performed by applying a step voltage to the devices Device i and Device ii obtained in example 1 and comparative example 1, and as shown in fig. 3, the contrast at 570nm was about 40% for Device i and 35% for Device ii, indicating that the contrast, i.e., the degree of discoloration, was better for Device i than for Device ii. The response time of Device I at 570nm is about 0.3s, and the response time of Device II at 570nm is about 2.3s, which shows that the response speed of Device I is significantly better than that of Device II. It is demonstrated that the electrochromic Device i using the novel electrolyte has more excellent electrochromic properties.

The ultraviolet absorption test, the contrast test and the response time test are realized by an ultraviolet absorption instrument and an electrochemical workstation. The test wavelength range is 400nm-800nm, the model of the ultraviolet absorption instrument is UV-1800, and the model of the electrochemical workstation is chi660 e.

Example 2

(1) Preparation of conductive polymer (ProDOT) solution: a chloroform solution of the conductive polymer (5 mg/ml) was prepared in a 10ml volumetric flask.

(2) Preparation of conductive polymer film: preparing the conductive polymer film by using a spin coating method, firstly placing the ITO glass on a spin coater, then uniformly dripping the prepared conductive polymer solution in the step (1) on the surface of the ITO glass by using a dropper, starting the spin coater at the rotating speed of 1000r/min for 60s, and stopping to prepare the conductive polymer film.

(3) Containing Fe³⁺Preparing the liquid electrolyte: the total concentration of 0.1mol/LFeCl was prepared in a 10ml volumetric flask₃And TBAP in a mixed acetonitrile solution, in which FeCl₃The concentration is 0.03mol/L, and the TBAP concentration is 0.07 mol/L.

(4) Preparing an electrochromic device: (2) the ITO glass spin-coated with the conductive polymer film prepared in the step (3) is used as a working electrode, the blank ITO glass is used as a counter electrode, the electrolyte prepared in the step (3) is used as device electrolyte, and 3M glue is used as a packaging means for assembling the electrochromic device.

The resulting Device is called Device iii.

The devices Device III and Device II obtained in example 2 and comparative example 1 were tested for contrast and response time by applying a step voltage, as shown in FIG. 4, the contrast at 570nm was about 45% for Device III and 35% for Device II, indicating that the contrast, i.e., the degree of discoloration, was better for Device III than for Device II. The response time of Device III at 570nm is about 1.0s, and the response time of Device II at 570nm is about 2.3s, which shows that the response speed of Device III is significantly better than that of Device II. It is demonstrated that the electrochromic Device iii using the novel electrolyte has more excellent electrochromic properties.

Example 3

(1) Preparation of conductive polymer (ProDOT) solution: a chloroform solution of the conductive polymer (5 mg/ml) was prepared in a 10ml volumetric flask.

(2) Preparation of conductive polymer film: preparing the conductive polymer film by using a spin coating method, firstly placing the ITO glass on a spin coater, then uniformly dripping the prepared conductive polymer solution in the step (1) on the surface of the ITO glass by using a dropper, starting the spin coater at the rotating speed of 1000r/min for 60s, and stopping to prepare the conductive polymer film.

(3) Preparing a solid electrolyte containing high-standard electrode potential ions: mixing 2.1g PMMA and 5mL PC at 60 ℃ for swelling for 5 days, and then adding 10mL of acetonitrile solution mixed by high standard electrode potential ions and TBAP with the total concentration of 0.1mol/L, wherein FeCl₃The concentration is 0.05mol/L, the TBAP concentration is 0.05mol/L, and acetonitrile is removed by a rotary evaporator after ultrasonic homogenization to prepare the solid electrolyte.

(4) Preparing an electrochromic device: (2) the ITO glass spin-coated with the conductive polymer film prepared in the step (3) is used as a working electrode, the blank ITO glass is used as a counter electrode, the electrolyte prepared in the step (3) is used as device electrolyte, and 3M glue is used as a packaging means for assembling the electrochromic device.

The resulting Device is called Device iv.

The contrast and response time tests were performed by applying a step voltage to the devices Device IV and Device II obtained in example 3 and comparative example 1, and as shown in FIG. 5, the contrast at 570nm was about 50% for Device IV and 35% for Device II, indicating that the contrast, i.e., the degree of discoloration, was better for Device IV than for Device II. The response time of the Device IV at 570nm is about 1.0s, and the response time of the Device II at 570nm is about 2.3s, which shows that the response speed of the Device IV is obviously superior to that of the Device II. It is demonstrated that the electrochromic Device iv using the novel electrolyte has more excellent electrochromic properties.