阅读说明：本技术 一种基于透明金属网电极的电致变色器件 (Electrochromic device based on transparent metal mesh electrode ) 是由 王振 李善林 陈永 韦雅庆 于 2021-07-28 设计创作，主要内容包括：本发明提供一种基于透明金属网电极的电致变色器件,包括四层结构,依次为第一层、第二层、第三层和第四层,所述第一层为透明导电玻璃,所述第三层为锌网或镀锌金属网格；所述第四层为透明不导电玻璃,用于放置第三层；所述第二层为空腔,用于容纳电解质,所述电解质为锌盐或氧化锌与强碱络合反应生成的络合离子电解质；所述第一层和第三层连接有导线。本发明制备的电致变色器件,降低了离子极化的影响,获得更好的沉积均匀性,强碱电解质降低了副产物Zn(OH)-(2)和ZnO对器件可逆性的影响,具有很好的透过率调节能力,更好实现电致变色,使得器件更好应用。(The invention provides an electrochromic device based on a transparent metal mesh electrode, which comprises a four-layer structure, namely a first layer, a second layer, a third layer and a fourth layer in sequence, wherein the first layer is transparent conductive glass, and the third layer is a zinc mesh or a galvanized metal grid; the fourth layer is transparent non-conductive glass and is used for placing the third layer; the second layer is a cavity and is used for accommodating electrolyte, and the electrolyte is complex ion electrolyte generated by the complex reaction of zinc salt or zinc oxide and strong base; the first layer and the third layer are connected with a conducting wire. The electrochromic device prepared by the invention reduces the influence of ion polarization, obtains better deposition uniformity, and reduces by-products Zn (OH) by using strong base electrolyte 2 And ZnO has good reversibility to the device, has good transmittance regulating ability, and can better realize electrochromism, so thatThe device is better applied.)

1. An electrochromic device based on a transparent metal mesh electrode is characterized by comprising a four-layer structure which is a first layer, a second layer, a third layer and a fourth layer in sequence,

the first layer is a transparent conductive glass,

the third layer is a zinc mesh or a galvanized metal mesh, and the transparency is 50% -99%;

the fourth layer is transparent non-conductive glass and is used for placing the third layer;

the second layer is a cavity and is used for accommodating electrolyte, and the electrolyte is Zn (OH) generated by the complexation reaction of zinc salt or zinc oxide and strong base₄ ^2-And the first layer and the third layer are connected with a conducting wire.

2. The electrochromic device based on transparent metal mesh electrode as claimed in claim 1, wherein the concentration of zinc ions in the electrolyte preparation raw material before the complexation reaction is 0.08-1M.

3. Electrochromic device based on transparent metal mesh electrodes, according to claim 1 or 2, characterized in that prior to the complexation reaction, Zn is present in the electrolyte preparation raw material²⁺And OH^-Mole ofThe ratio is 1: 4.01-20.

4. The electrochromic device based on transparent metal mesh electrode as claimed in claim 3, wherein the concentration of Zn ion in the electrolyte preparation raw material is 0.1M, Zn before the complexation reaction²⁺And OH^-In a molar ratio of 1: 10.

5. the electrochromic device based on transparent metal mesh electrode as claimed in claim 1, wherein the zinc mesh or zinc-plated metal grid has mesh wire inner diameter of 1-1000 μm and mesh opening of 5-300 mesh.

6. The electrochromic device based on transparent metal mesh electrode as claimed in claim 1, wherein the transparency of the zinc mesh or zinc-plated metal mesh is 80-95%.

7. The electrochromic device based on transparent metal mesh electrode as recited in claim 1, wherein the electrolyte is an aqueous electrolyte or a gel electrolyte, and the gel comprises PVA, sodium alginate, cellulose.

8. The electrochromic device based on transparent metal mesh electrode as claimed in claim 1, characterized in that the zinc salt comprises ZnCl₂、ZnSO₄The strong base comprises at least one of KOH and NaOH, and the transparent conductive glass comprises at least one of FTO glass, ITO glass, AZO glass and transparent conductive graphene glass.

9. The electrochromic device based on transparent metal mesh electrode as claimed in claim 1, wherein the preparation of the electrolyte: adding ZnO or zinc salt into deionized water, stirring, adding strong base while stirring, and adding deionized water to desired volume when the reaction is complete and the solution becomes clear.

10. The electrochromic device based on the transparent metal mesh electrode as claimed in any one of claims 1 to 9, wherein the preparation method of the electrochromic device comprises: the zinc mesh or the zinc-plated metal grid is placed on transparent non-conductive glass, rubber glue is used for fixing the periphery of the zinc mesh or the zinc-plated metal grid, the height of the rubber glue is set to be 1-5mm, the transparent non-conductive glass is pasted on the prepared transparent non-conductive glass in the right side and the opposite side, two leads are respectively led out, the periphery of the transparent non-conductive glass is sealed by ultraviolet curing glue, a small opening is reserved, after the transparent non-conductive glass is cured, electrolyte is injected into the cavity through the small opening by an injector, and finally the ultraviolet curing glue is used for sealing the opening, so that the electrochromic device of the zinc metal mesh is prepared.

Technical Field

The invention relates to the field of electrochromism, in particular to an electrochromism device based on a transparent metal mesh electrode.

Background

Electrochromism is a leading-edge technology in a family of color generation technologies, reversible light absorption or light scattering is generated by using materials under the action of an external electric field or current so as to generate reversible color or optical property change, and a corresponding photoelectric device is called an electrochromic device. Due to artificial dynamic reversible light regulation, electrochromic devices have broad development prospects and great commercial values in the field of intelligent windows. Installing electrochromic intelligent windows in buildings and automobiles can not only provide privacy function, but also realize energy-saving function by reducing the requirements of heating, ventilation and air conditioning. For example, installing smart windows in an office building saves on average 10% of energy over static low-e windows; the adjustable sunroof may also reduce air conditioning consumption in the vehicle, which is particularly important in electric vehicles. In the last 40 years, most of the research on electrochromic devices has focused on electrochromic materials, mainly comprising viologens, polymers and transition metal oxides, which undergo a color change upon application of different voltages. However, the organic electrochromic material has the disadvantages of unstable chemical property, high requirement on the condition of the material and the like, thereby influencing the application of the organic electrochromic material; the transition metal oxide has a long response time, and repeated insertion/extraction of ions into/from the crystal lattice can also cause collapse of the structure of the electrochromic material, so that the electrochromic material can gradually fail due to the decay of performance. In conclusion, despite extensive research, organic/inorganic electrochromic materials have not been commercialized on a large scale due to problems in color, cost, durability, and color change switching speed.

Metals are highly opaque when they are only 20-30 nm thick due to their high extinction coefficient, and many metals are chemically inert, strongly light-fast and color neutral, which make them ideal materials for dynamic smart windows. On the other hand, metal ions generate a metal layer on the surface of the solid through electrochemical reduction reaction and an electric crystallization process, and meanwhile, the metal layer can enter the electrolyte through electrochemical oxidation reaction and an electric dissolution process. Therefore, the metal is used as an optical active material to prepare a novel electrochromism intelligent window capable of being electrochemically and reversibly deposited. For example, Stanford Michael D. McGehe team modified ITO glass with Pt particlesGlass as a working electrode, glass with a copper metal frame adhered thereto as a counter electrode, and a Cu-Pb gel electrolyte as an electrolyte layer were assembled to a length of 25cm²The metal deposition electrochromic intelligent window can be in a transparent state (79-85 percent) and an opaque state (with neutral color) ((<5%) without significant degradation in contrast, color change time and uniformity of the device after 5500 cycles (Joule2017,1, 133-.

Although metal deposition electrochromic smart windows have many excellent characteristics, one of the major challenges is the difficulty in achieving uniform electrodeposition over large area sizes. This is because the metal ions must diffuse laterally a long distance from the rim of the counter electrode to the center of the working electrode during electrodeposition. Under such conditions, the metal will preferentially electrodeposit on the edges of a large area smart window, or it takes a long time to achieve uniform coloration of the color changing window. To solve this problem, the Christopher J.Narile team, university of Nevada uses a NiO film as the counter electrode, Cu²⁺And Li⁺The mixed ions are used as electrolyte ions, and Li + is inserted into NiO of the counter electrode to complete a current loop in the discoloring metal dissolution process of the electrochromic electrode. However, there is a problem that Cu is inserted into NiO except Li + at the counter electrode at this time²⁺、Bi³⁺The electrodeposition of (a) is a strong side reaction which also results in non-uniform device discoloration. The Narile team then spin-coated BTD on the NiO surface to suppress Cu²⁺、Bi³⁺However, the use of BTD inhibitors has low time durability and manufacturing yield of this method (Nature Energy,2019,4, 223-.

Disclosure of Invention

In view of the above, the present invention provides an electrochromic device based on a transparent metal mesh electrode, which solves the above problems.

The technical scheme of the invention is realized as follows: the utility model provides an electrochromic device based on transparent metal mesh electrode, includes the four layers structure, is first layer, second floor, third layer and fourth layer in proper order, first layer is transparent conductive glass, the third layer is zinc mesh or zinc-plated metal mesh, and the transparency is 50% ~ to99%, preferably 80% to 95%; the fourth layer is transparent non-conductive glass and is used for placing the third layer; the first layer and the third layer are connected with a lead; the second layer is a cavity and is used for accommodating electrolyte, and the electrolyte is Zn (OH) generated by the complexation reaction of zinc salt or zinc oxide and excessive strong base₄ ^2-A complex ion electrolyte, the concentration of the zinc ion being 0.08-1M, preferably 0.1M, Zn²⁺With OH^-In a molar ratio of 4.01 to 20, preferably 1: 10. if the concentration of zinc ions is too low, the regulation effect is poor; if the concentration of strong alkali is insufficient, complex ions cannot be stably formed, a large amount of precipitates appear, and the regulation effect is poor; and the electrolyte concentration is too high, so that the cost is high, the required strong alkali concentration is high, the alkalinity is too strong, and the glass is easy to corrode.

Furthermore, the inner diameter of the mesh of the zinc mesh or the galvanized metal grid is 1-1000 μm, and the mesh is 5-300 meshes.

Further, the electrolyte is an aqueous electrolyte or a gel electrolyte, and the gel comprises at least one of PVA, sodium alginate and cellulose.

Further, the zinc salt includes ZnCl₂、ZnSO₄The strong base comprises at least one of KOH and NaOH.

Further, the transparent conductive glass is rigid FTO glass, ITO glass, AZO glass, transparent conductive graphene glass, or FTO glass, ITO glass, AZO glass modified by nanocrystals (Pt, Au, ITO) or conductive polymers (polyaniline, polythiophene, polypyrrole), or a flexible transparent conductive electrode (PET/ITO, PET/graphene electrode, PET/conductive polymer).

Further, the preparation of the electrolyte comprises the following steps: adding ZnO or zinc salt into deionized water, stirring, adding strong base while stirring, and adding deionized water to desired volume when the reaction is complete and the solution becomes clear.

The preparation method of the electrochromic device comprises the following steps: the zinc mesh or the zinc-plated metal grid is placed on transparent non-conductive glass, rubber glue is used for fixing the periphery of the transparent non-conductive glass, the height of the rubber glue is set to be 1-5mm, the transparent conductive glass is pasted on the prepared transparent non-conductive glass carrying the zinc mesh or the zinc-plated metal grid in a right-to-right mode, two leads are respectively led out, the periphery of the transparent non-conductive glass is sealed through ultraviolet curing glue, a small opening is reserved, after the transparent non-conductive glass is cured, electrolyte is injected into the cavity through the small opening through an injector, and finally the cavity is sealed through the ultraviolet curing glue, so that the electrochromic device of the zinc metal mesh is manufactured.

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

the invention adopts transparent conductive glass as a working electrode, selects a zinc net or a galvanized metal grid as a counter electrode, combines a zinc source with certain concentration and Zn (OH) generated by excessive strong base complex reaction₄ ^2-Complexing ion electrolyte to prepare the zinc metal grid electrochromic device, reduces the influence of ion polarization, obtains better deposition uniformity, and reduces by-products Zn (OH) by strong base electrolyte₂And ZnO has the reversible effect on the device, has good transmittance adjusting capability, better realizes electrochromism, and enables the device to be better applied.

Compared with the prior metal deposition, the Zn (OH) prepared under the strong alkaline condition₄ ^2-The complex ion electrolyte has better reversibility because Zn (OH) is reduced under strong alkaline conditions₂And ZnO and the like on the reversibility of the device.

Drawings

FIG. 1 is a diagram of a metal mesh electrochromic device of the present invention;

FIG. 2 is a graph showing a comparison of transmittance before and after 0.8V deposition for 30s and 0.8V peeling for 30s for the electrochromic device made in example 1;

FIG. 3 is an i-t plot of a-0.8V constant voltage deposition for an electrochromic device made in example 1;

FIG. 4 is an i-t plot of 0.8V constant voltage peel-off for the electrochromic device made in example 1.

FIG. 5 is a graph comparing the transmittance before and after 30s of 0.8V deposition and 30s of 0.8V stripping for the device made in comparative example 1.

Detailed Description

In order to better understand the technical content of the invention, specific examples are provided below to further illustrate the invention.

The experimental methods used in the examples of the present invention are all conventional methods unless otherwise specified.

The materials, reagents and the like used in the examples of the present invention can be obtained commercially without specific description.

Example 1

As shown in fig. 1, an electrochromic device based on a transparent metal mesh electrode is composed of a four-layer structure, which is sequentially provided with a first layer 1, a second layer 2, a third layer 3 and a fourth layer 4,

the first layer 1 is made of transparent conductive glass and is made of FTO glass.

The third layer 3 is a zinc mesh, the inner diameter of the mesh is 1-1000 μm, the mesh is 5-300 meshes, and the transparency is 50% -99%, in this embodiment, the inner diameter of the mesh is 50 μm, the mesh is 50 meshes, and the transparency is 80% -95%.

The fourth layer 4 is made of transparent non-conductive glass and used for placing the third layer 3; the second layer 2 is a cavity for accommodating an electrolyte; the first layer and the third layer are connected with a conducting wire.

The preparation method comprises the following steps:

(1) preparing an electrolyte: 0.1mol of ZnCl₂Adding into a small amount of deionized water, stirring and mixing, adding 1mol of KOH while stirring, and carrying out complex reaction to generate Zn (OH)₄ ^2-When the reaction is completed and the solution becomes clear, adding deionized water to dilute until the volume is 1L to obtain 0.1M Zn (OH)₄ ^2-A complex ionic electrolyte.

(2) Preparing an electrochromic device: the zinc mesh (third layer) is placed on the transparent non-conductive glass (fourth layer), the periphery of the zinc mesh (third layer) is fixed by using rubber adhesive, the height of the rubber adhesive is set to be 1-5mm, the height of the rubber adhesive is set to be 2mm in the embodiment, the transparent conductive glass (first layer) is attached to the prepared transparent non-conductive glass (third layer-fourth layer) carrying the zinc mesh in a face-to-face mode, two leads are respectively led out, the periphery of the transparent conductive glass (first layer) is sealed by using ultraviolet curing adhesive, a small opening is reserved for injecting electrolyte, after the transparent conductive glass (first layer) is cured, the electrolyte is injected into a cavity (second layer) through an injector by using the small opening, and finally the ultraviolet curing adhesive is used for sealing, so that the electrochromic device of the zinc metal mesh is prepared.

The working principle is as follows: in an initial state, the device is in a transparent state, voltage is applied through a wire connected from the transparent conductive glass and the zinc grid, when negative pressure (-0.1 to-1.2V) is applied, metal on the zinc grid is dissolved in electrolyte, zinc ions in the electrolyte are uniformly electrodeposited on the transparent conductive glass, and when a zinc layer with the thickness of 20-30 nm is deposited, the zinc layer is completely opaque (the transparency is less than 5%), so that the electrochromic device can realize the transition from transparent to opaque.

When a voltage (+ 0.1-1.2V) is applied, zinc deposited on the transparent conductive glass is dissolved in the electrolyte, the transparent conductive glass is changed back to a transparent state, zinc ions of the electrolyte are electrodeposited on the zinc grid again, the change of the transparency of the zinc grid is small, and at the moment, the electrochromic device can be changed from non-transparent to transparent.

As shown in FIG. 2, a graph showing the transmittance after-0.8V deposition for 30s and after-0.8V peeling-off for 30s was obtained by using the electrochromic device manufactured in example 1. From the graph, the change in transmittance of deposition and peeling can be seen, indicating that the device has good transmittance adjustment capability.

As shown in FIG. 3, using the electrochromic device manufactured in example 1, i-t graphs of constant voltage deposition of-0.8V were tested, and from the graphs, voltage variation of the deposition process was seen, indicating the continuity of the deposition process.

As shown in fig. 4, the i-t curve of the 0.8V constant voltage peeling was measured using the electrochromic device manufactured in example 1, and from the i-t curve, the voltage change of the peeling process was seen, indicating that the device could be reversibly peeled.

In addition, on the basis of embodiment 1, the first layer 1 may also be a rigid ITO glass, AZO glass, transparent conductive graphene glass, or a nanocrystal (Pt, Au, ITO) or conductive polymer (polyaniline, polythiophene, polypyrrole) modified FTO glass, ITO glass, AZO glass, or a flexible transparent conductive electrode (PET/ITO, PET/graphene electrode, PET/conductive polymer); the electrolyte can also be gel electrolyte (the gel is PVA, sodium alginate and cellulose); ZnCl₂Can also be replaced by ZnSO₄Or ZnO; KOH solutionNaOH can be replaced by the method; the third layer 3 of zinc mesh may be replaced by a galvanized metal mesh.

Example 2

The main difference from example 1 is in the electrolyte preparation: 0.08mol of ZnCl₂Adding into a small amount of deionized water, stirring and mixing, then adding 1.6mol of KOH, stirring while adding, and carrying out complex reaction to generate Zn (OH)₄ ^2-When the reaction is completed and the solution becomes clear, adding deionized water to dilute until the volume is 1L to obtain 0.08M Zn (OH)₄ ^2-A complex ionic electrolyte. The results show that the product has reversibility and good electrorheological effect.

Example 3

The main difference from example 1 is in the electrolyte preparation: 1mol of ZnCl₂Adding into a small amount of deionized water, stirring and mixing, adding 4.1mol of KOH while stirring, and carrying out complex reaction to generate Zn (OH)₄ ^2-When the reaction is completed and the solution becomes clear, adding deionized water to dilute until the volume is 1L to obtain 1M Zn (OH)₄ ^2-A complex ionic electrolyte. The results show that the product has reversibility and good electrorheological effect.

Comparative example 1

The main differences from example 1 are: the electrolyte was replaced with 0.1M aqueous zinc chloride solution. The results show that the deposition is irreversible (as shown in figure 5).

Comparative example 2

The main differences from example 1 are: the third layer of metal net is a nano copper net, the inner diameter of the net wire is 50 μm, and the mesh is 50 meshes; the electrolyte used was 0.1M aqueous copper chloride. The first and fourth layers were the same as in example 1. The results show irreversible deposition.

Comparative example 3

The main difference from example 1 is in the electrolyte preparation: 0.005mol of ZnCl₂Adding into a small amount of deionized water, stirring and mixing, then adding 0.05mol of KOH, stirring while adding, and carrying out complex reaction to generate Zn (OH)₄ ^2-When the reaction is completed and the solution becomes clear, deionized water is added to dilute the solution to a constant volume of 1L to obtain 0.005M of Zn (OH)₄ ^2-Complex ion electrolyte. The results show that there is no control effect and no deposition.

Comparative example 4

The main difference from example 1 is in the electrolyte preparation: 0.1mol of ZnCl₂Adding into a small amount of deionized water, stirring, adding 0.3mol of KOH, stirring while adding, and adding Zn²⁺With OH^-Is less than 0.25, forms Zn (OH)₂Precipitation and poor regulation effect of a solution turbidity device, and the prepared solution can not be used as an electrolyte.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.