阅读说明：本技术 一种全固态电致变色器件及其制备方法 (All-solid-state electrochromic device and preparation method thereof ) 是由 肖秀娣 刘杨彪 王济熙 蔡雪松 盛贵章 徐刚 于 2020-08-07 设计创作，主要内容包括：本发明公开了一种全固态电致变色器件及其制备方法。该制备方法包括如下步骤：(1)在第一透明导电膜上制备电致变色层；(2)先制备离子储存层的纳米颗粒,将离子储存层的纳米颗粒分散到含有电解质的聚合物溶液中形成浆料,将浆料涂覆于电致变色层上,把涂覆了浆料的电致变色层加热固化,制备得到电解质与离子储存层的复合层；(3)将第二透明导电膜放到电解质与离子储存层的复合层上封装,得到全固态电致变色器件。本发明利用多孔电致变色层释放离子嵌入迁出的应力,提高电致变色薄膜的循环寿命,通过把含有电解质的离子储存层纳米颗粒嵌入电致变色薄膜的多孔结构中,在增加电解质接触面积的同时,缩短离子传输长度,以提高响应速度。(The invention discloses an all-solid-state electrochromic device and a preparation method thereof. The preparation method comprises the following steps: (1) preparing an electrochromic layer on the first transparent conductive film; (2) firstly, preparing nano particles of an ion storage layer, dispersing the nano particles of the ion storage layer into a polymer solution containing electrolyte to form slurry, coating the slurry on an electrochromic layer, heating and curing the electrochromic layer coated with the slurry, and preparing a composite layer of the electrolyte and the ion storage layer; (3) and placing the second transparent conductive film on a composite layer of the electrolyte and the ion storage layer for packaging to obtain the all-solid-state electrochromic device. According to the invention, the porous electrochromic layer is used for releasing the stress of ion embedding and emigration, the cycle life of the electrochromic film is prolonged, and the ion storage layer nanoparticles containing electrolyte are embedded into the porous structure of the electrochromic film, so that the contact area of the electrolyte is increased, and the ion transmission length is shortened, thereby improving the response speed.)

1. A preparation method of an all-solid-state electrochromic device is characterized by comprising the following steps:

(1) preparing an electrochromic layer on the first transparent conductive film by adopting a physical vapor deposition method;

(2) preparing nano particles of the ion storage layer by a hydrothermal method, a coprecipitation method or a thermal injection method, dispersing the nano particles of the ion storage layer into a polymer solution containing electrolyte to form slurry, coating the slurry on the electrochromic layer obtained in the step (1), heating and curing the electrochromic layer coated with the slurry, and preparing a composite layer of the electrolyte and the ion storage layer on the electrochromic layer;

(3) and (3) placing the second transparent conductive film on the composite layer of the electrolyte and the ion storage layer obtained in the step (2) for packaging to obtain the all-solid-state electrochromic device.

2. The preparation method of the all-solid-state electrochromic device according to claim 1, wherein the specific steps of the step (2) are as follows: preparing nano particles of the ion storage layer by a hydrothermal method, a coprecipitation method or a thermal injection method, dispersing the nano particles of the ion storage layer into a polymer solution containing electrolyte to form slurry, coating the slurry on the electrochromic layer obtained in the step (1) by using a spin coating method or a dip coating method, drying the electrochromic layer coated with the slurry at 40-60 ℃ for 5-7 hours, heating and curing, and preparing a composite layer of the electrolyte and the ion storage layer on the electrochromic layer.

3. The method for preparing an all-solid-state electrochromic device according to claim 1 or 2, wherein the electrolyte is selected from one of inorganic ion conductor selected from LiClO, ionic liquid and ion conductive polymer₄,LiPF₆And LiBF₄The ionic liquid is selected from one of imidazole salt ionic liquid, piperidine salt ionic liquid and pyridine salt ionic liquid, and the ionic conductive polymer is selected from one of PVDF-based gel polymer, PEO-based gel polymer and PAN-based gel polymer.

4. The method for preparing an all-solid-state electrochromic device according to claim 1 or 2, wherein the polymer is selected from one of polyethylene glycol, polymethyl methacrylate and polyurethane, the molar concentration of the electrolyte is 1-10M, the mass fraction of the polymer is 1-10%, and the solvent in the polymer solution is propylene carbonate and/or acetonitrile.

5. The method of claim 1, wherein the porous film of the electrochromic layer has a structure of a pillar, a spiral, a dendrite, a zigzag, a C, or a Y structure.

6. The method of claim 5, wherein the porous membrane of the electrochromic layer and the material of the ion storage layer are selected from WO₃、MoO₃、TiO₂、Nb₂O₅、Ta₂O₅、NiO、Co₃O₄、V₂O₅And Ir₂O₃Two complementary materials.

7. The method for preparing an all-solid electrochromic device according to claim 1, wherein the first transparent conductive film is made of one material selected from ITO, FTO, AZO, Ag, Au and Cu, and the second transparent conductive film is made of one material selected from ITO, FTO, AZO, Ag, Au and Cu.

8. The all-solid-state electrochromic device prepared by the preparation method of the all-solid-state electrochromic device according to claim 1, wherein the all-solid-state electrochromic device is composed of a first transparent conductive film, an electrochromic layer, a composite layer of an electrolyte and an ion storage layer, and a second transparent conductive film in sequence from bottom to top.

9. The all-solid-state electrochromic device according to claim 8, wherein the first transparent conductive film has a thickness of 30 to 150nm, the electrochromic layer has a thickness of 100 to 1000nm, the composite layer of the electrolyte and the ion storage layer has a thickness of 100 to 1000nm, and the second transparent conductive film has a thickness of 30 to 150 nm.

Technical Field

The invention relates to the technical field of electrochromic devices, in particular to an all-solid-state electrochromic device and a preparation method thereof.

Background

In China, the energy consumption of buildings accounts for about 30% of the total energy consumption of the society, wherein the energy consumption of heating and air conditioning accounts for 55% of the energy consumption of the buildings. In modern buildings, glass occupies an increasingly large area of the outer wall, and heat transfer through the glass window respectively occupies 48% and 71% in winter and summer according to measurement and calculation, so that the door and window energy saving has an obvious effect on reducing building energy consumption.

The intelligent window taking color change as a working principle is a newly emerging door and window energy-saving technology in recent years, such as a thermochromatic intelligent window, an electrochromic intelligent window, a gas-colored intelligent window and the like. The electrochromic intelligent window has different absorption capacities on light when the electrochromic layer film is embedded and emigrated in ions under low direct current voltage, so that the sunlight is adjusted, and the intelligent heat insulation purpose is achieved. Electrochromic glass generally consists of a five-layer structure, namely a transparent conductive layer, an electrochromic layer, an electrolyte layer, an ion storage layer and a transparent conductive layer. However, in order to achieve fast response times, the electrolyte layer is typically a liquid electrolyte, and the susceptibility to leakage and flammability of the liquid electrolyte has been a concern for electrochromic windows.

To solve this problem, the development of all-solid electrolytes has been a goal pursued. For example, CN110045558A and CN106444203A achieve solidification of the electrolyte by a method of sputtering a compound containing lithium once, which greatly prolongs the response time and reduces the stability of the electrochromic device due to the compact structure of the solid electrolyte, the low ion transport rate and the expansion stress thereof, and in addition, the contact area of the solid electrolyte with the electrochromic layer and the ion storage layer is limited, which is also a great weak point influencing the response time, and thus the technical problem needs to be solved.

Disclosure of Invention

The invention provides an all-solid-state electrochromic device and a preparation method thereof, aiming at solving the problems in the prior art. According to the invention, the porous electrochromic layer is used for releasing the stress of ion embedding and emigration, the cycle life of the electrochromic film is prolonged, and the ion storage layer nanoparticles containing electrolyte are embedded into the porous structure of the electrochromic film, so that the contact area of the electrolyte is increased, and the ion transmission length is shortened, thereby improving the response speed.

The invention provides a preparation method of an all-solid-state electrochromic device, which comprises the following steps:

(1) preparing an electrochromic layer on the first transparent conductive film by adopting a physical vapor deposition method;

(2) preparing nano particles of the ion storage layer by a hydrothermal method, a coprecipitation method or a thermal injection method, dispersing the nano particles of the ion storage layer into a polymer solution containing electrolyte to form slurry, coating the slurry on the electrochromic layer obtained in the step (1), heating and curing the electrochromic layer coated with the slurry, and preparing a composite layer of the electrolyte and the ion storage layer on the electrochromic layer;

(3) and (3) placing the second transparent conductive film on the composite layer of the electrolyte and the ion storage layer obtained in the step (2) for packaging to obtain the all-solid-state electrochromic device.

The invention prepares the electrochromic layer with the porous nano structure by introducing the vacuum oblique deposition technology (physical vapor deposition method), the film prepared by the method has the advantages of high porosity, generally amorphous state, controllable micro-nano structure and large expandable space, is beneficial to the embedding and the separating of ions in the color changing process and improves the electrochemical reaction rate, thereby improving the color changing speed and the color changing efficiency, the loose structure of the film provides a space for releasing the stress generated when the ions are embedded and separated, the problem of film falling caused by volume expansion and internal stress is avoided, and the circulating stability is fundamentally improved. By adsorbing the electrolyte material on the ion storage layer nanoparticles, the contact area of the electrolyte is increased, and the response speed is improved. More importantly, the ion storage layer nanoparticles adsorbed with the electrolyte are filled in the gaps of the electrochromic porous structure, so that the distance between the electrolyte and the electrochromic layer and the distance between the electrolyte and the ion storage layer are greatly shortened, the response speed is further improved, and the electrochromic structure is simplified.

Preferably, the specific steps of step (2) are: preparing nano particles of the ion storage layer by a hydrothermal method, a coprecipitation method or a thermal injection method, dispersing the nano particles of the ion storage layer into a polymer solution containing electrolyte to form slurry, coating the slurry on the electrochromic layer obtained in the step (1) by using a spin coating method or a dip coating method, drying the electrochromic layer coated with the slurry at 40-60 ℃ for 5-7 hours, heating and curing, and preparing a composite layer of the electrolyte and the ion storage layer on the electrochromic layer. The particle size of the ion storage layer nano particles is 5-25 nm.

The method combines the characteristic that the inclined deposition technology can prepare the ordered porous structure membrane, attaches the electrolyte to the ion storage layer nano particles, and then embeds the ion storage layer nano particles containing the electrolyte into the porous structure of the electrochromic layer. The porous electrochromic layer is utilized to release the stress of ion embedding and emigration, and the cycle life of the electrochromic film is prolonged. By embedding the electrolyte-containing ion storage layer nanoparticles into the porous structure, the ion transport length is shortened while the electrolyte contact area is increased, so that the response speed is improved.

Preferably, the electrolyte is selected from one of inorganic ion conductor, ionic liquid and ion conductive polymer, and the inorganic ion conductor is selected from LiClO₄,LiPF₆And LiBF₄The ionic liquid is selected from one of imidazole salt ionic liquid, piperidine salt ionic liquid and pyridine salt ionic liquid, and the ionic conductive polymer is selected from one of PVDF-based gel polymer, PEO-based gel polymer and PAN-based gel polymer.

Preferably, the polymer is selected from one of polyethylene glycol (PEG), polymethyl methacrylate (PMMA) and Polyurethane (PU), the molar concentration of the electrolyte is 1-10M, the mass fraction of the polymer is 1-10%, and the solvent in the polymer solution is propylene carbonate and/or acetonitrile.

Preferably, the porous membrane of the electrochromic layer has a structure of a columnar structure, a spiral structure, a dendritic structure, a zigzag structure, a C-type structure or a Y-type structure. The vacuum inclined deposition technology is realized by utilizing the inclination of 0-90 degrees and the rotation of 0-360 degrees of the angle of a substrate in a three-dimensional space in the deposition process of the electrochromic film, and at least one loose porous structure of a columnar structure, a spiral structure, a dendritic structure, a zigzag structure, a C-shaped structure and a Y-shaped structure with the inclination of 0-90 degrees is obtained by using a magnetron sputtering method, an electron beam evaporation method or a laser pulse deposition method.

Further preferably, the materials of the porous membrane and the ion storage layer of the electrochromic layer are selected from WO₃、MoO₃、TiO₂、Nb₂O₅、Ta₂O₅、NiO、Co₃O₄、V₂O₅And Ir₂O₃When the electrochromic layer is a cathode electrochromic material, the ion storage layer is selected from an anode electrochromic material.

Preferably, the first transparent conductive film material is selected from one of ITO (indium-doped tin oxide), FTO (fluorine-doped tin oxide), AZO (aluminum-doped zinc oxide), Ag, Au and Cu, and the second transparent conductive film material is selected from one of ITO (indium-doped tin oxide), FTO (fluorine-doped tin oxide), AZO (aluminum-doped zinc oxide), Ag, Au and Cu.

The invention also provides the all-solid-state electrochromic device prepared by the preparation method, which sequentially consists of the first transparent conductive film, the electrochromic layer, the composite layer of the electrolyte and the ion storage layer and the second transparent conductive film from bottom to top.

Preferably, the thickness of the first transparent conductive film is 30-150 nm, the thickness of the electrochromic layer is 100-1000 nm, the thickness of the composite layer of the electrolyte and the ion storage layer is 100-1000 nm, and the thickness of the second transparent conductive film is 30-150 nm.

The invention has the beneficial effects that:

1. the all-solid-state electrochromic device prepared by the preparation method provided by the invention has the characteristics of compact structure and short response time, can be used in the technical field of intelligent windows and displays, and has good application prospect.

2. The electrochromic layer is a porous membrane prepared by utilizing an inclined deposition technology in physical vapor deposition, and a composite layer of an electrolyte and an ion storage layer is formed by filling ion storage layer nano particles containing the electrolyte into the porous membrane. The porous membrane prepared by the oblique deposition technology is an amorphous and regular porous structure, and the regular porous structure provides a filling space of nano particles and a stress release space for ion embedding/emigration. Because the contact area and the transmission distance between the electrolyte and the electrochromic layer and between the electrolyte and the ion storage layer are shortened, the response speed is greatly improved, and simultaneously, the release of stress delays the shedding of the porous membrane and improves the stability.

Drawings

FIG. 1 is a schematic structural diagram of an all-solid electrochromic device according to the present invention;

FIG. 2 is a schematic diagram of different porous structures prepared by oblique deposition according to an embodiment of the present invention;

FIG. 3 is SEM images of a columnar film obtained by the inclined deposition method of example 1 and a Z-shaped film obtained by the inclined deposition method of example 4;

description of reference numerals: 1. a first substrate; 2. a first transparent conductive film; 3. an electrochromic layer; 4. a composite layer of an electrolyte and an ion storage layer; 5. a second transparent conductive film; 6. a second substrate.

Detailed Description

The following examples are further illustrative of the present invention and are not intended to be limiting thereof. The equipment and reagents used in the present invention are, unless otherwise specified, conventional commercial products in the art.

As shown in fig. 1, the all-solid-state electrochromic device is composed of, from bottom to top, a first substrate 1, a first transparent conductive film 2, an electrochromic layer 3, a composite layer 4 of an electrolyte and ion storage layer, a second transparent conductive film 5, and a second substrate 6. The first transparent conductive film has a thickness of 30 to 150nm, the electrochromic layer has a thickness of 100 to 1000nm, the composite layer of the electrolyte and the ion storage layer has a thickness of 100 to 1000nm, and the second transparent conductive film has a thickness of 30 to 150 nm. A first transparent conductive film 2 is deposited on the first substrate 1 and a second transparent conductive film 5 is deposited on the second substrate 6. The first substrate 1 and the second substrate 6 are both flexible or rigid transparent substrates, and in the present invention the first substrate 1 and the second substrate 6 are preferably glass or PET (polyethylene terephthalate).