KR20180009019A - Electrochromic device - Google Patents

Abstract

The present invention relates to an electrochromic element with improved decolorization transmittance. The electrochromic element comprises: a first electrode; a second electrode facing the first electrode; an electrolyte layer interposed between the first electrode and the second electrode, and including an electrochromic material; and a porous layer interposed between at least one of the first and second electrodes and the electrolyte layer.

Description

[0001] Electrochromic device [0002]

The present invention relates to an electrochromic device, and more particularly, to an electrochromic device using an oxidation / reduction reaction.

BACKGROUND ART An electrochromic device is a device having characteristics of changing color and transmittance by an electrochemical reaction. When an electric potential difference is generated by external electric stimulation in the electrochromic device, ions or electrons contained in the electrolyte layer migrate into the electrochromic layer and an oxidation / reduction reaction occurs. By the oxidation / reduction reaction of the electrochromic layer, the color of the electrochromic device changes, and the degree to which visible light or infrared rays can be transmitted due to discoloration of the electrochromic material changes. Therefore, electrochromic devices are applied to optical shutters, reflective displays, automotive discoloration mirrors, and smart windows.

An object of the present invention is to provide an electrochromic device improved in discoloration transmittance.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an electrochromic device including a first electrode, a second electrode facing the first electrode, and a second electrode interposed between the first electrode and the second electrode An electrolyte layer including an electrochromic material, and a porous layer interposed between at least one of the first and second electrodes and the electrolyte layer.

According to one embodiment, the porous layer may comprise a porous metal oxide.

According to one embodiment, the electrochromic material of the electrolyte layer may comprise phenothiazine.

According to one embodiment, the porous layer may include at least one of TiO2 (titanium dioxide) and ITO (indium tin oxide).

According to one embodiment, the porous layer may include at least one of fluorinated tin oxide (FTO), ZnO, SnO2, and antimony-doped tin oxide.

According to one embodiment, the electrochromic device further comprises a electrochromic layer, wherein the porous layer is interposed between any one of the first and second electrodes and the electrolyte layer, and the electrochromic layer is disposed between the first and second electrodes May be interposed between the electrolyte layer and another one of the electrolyte layers.

According to one embodiment, the electrochromic layer may include tungsten oxide (Wox).

According to an aspect of the present invention, there is provided an electrochromic device including a first electrode and a first electrochromic layer on the first electrode, a second electrode opposing the first electrode, Wherein the electrolyte layer comprises a first electrochromic material and the electrolyte layer comprises a second electrochromic material, wherein the first electrochromic material comprises a first electrochromic material, The coating layer comprises a porous metal oxide.

According to an embodiment, the first electrochromic material may include an organic coloring material, and the second electrochromic material may include an inorganic coloring material.

The details of other embodiments are included in the detailed description and drawings.

According to the embodiments of the present invention, it is possible to provide an electrochromic device having improved discoloration transmittance.

1A is a cross-sectional view of an electrochromic device according to an embodiment of the present invention.
FIG. 1B is an enlarged view of FIG. 1A.
FIG. 2A is a view showing when the electrochromic materials of the electrochromic device are decolorized. FIG.
FIG. 2B is a view showing when the electrochromic materials of the electrochromic device are colored. FIG.
3 is a cross-sectional view of an electrochromic device according to an embodiment.
4 is a graph showing a reflection spectrum according to a comparative example.
5 is a graph showing a reflection spectrum using the electrochromic device of FIG.
6 is a graph showing a transmission spectrum using the electrochromic device of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms 'comprises' and / or 'comprising' mean that the stated element, step, operation and / or element does not imply the presence of one or more other elements, steps, operations and / Or additions.

In addition, the embodiments described herein will be described with reference to cross-sectional views and / or plan views, which are ideal illustrations of the present invention. In the drawings, the thicknesses of the films and regions are exaggerated for an effective description of the technical content. Thus, the shape of the illustrations may be modified by manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention are not limited to the specific forms shown, but also include changes in the shapes that are generated according to the manufacturing process. Thus, the regions illustrated in the figures have schematic attributes, and the shapes of the regions illustrated in the figures are intended to illustrate specific types of regions of the elements and are not intended to limit the scope of the invention.

1A is a cross-sectional view of an electrochromic device 1 according to an embodiment of the present invention. FIG. 1B is an enlarged view of FIG. 1A. 1A and 1B, an electrochromic device 1 includes a lower substrate 10, a lower electrode 20, a porous layer 30, an electrolyte layer 40, an electrochromic layer 50, 60, an upper substrate 70, and a sealant 80. The electrochromic device 1 may be transparent.

The lower substrate 10 may be opposed to and spaced from the upper substrate 70. The lower substrate 10 and the upper substrate 70 may be transparent substrates. For example, the lower substrate 10 and the upper substrate 70 may include, but are not limited to, glass substrates.

The lower electrode 20 may be disposed on the lower substrate 10. The upper electrode 60 may be disposed under the upper substrate 70. The upper electrode 60 and the lower electrode 20 may be opposed to each other. The upper electrode 60 and the lower electrode 20 may be provided as transparent electrodes. For example, the upper electrode 60 and the lower electrode 20 may comprise ITO or FTO. The lower electrode 20 may be patterned to include a plurality of sub-lower electrodes. The upper electrode 60 may be patterned to include a plurality of sub-upper electrodes.

The porous layer 30 may be disposed on the lower electrode 20. The porous layer 30 may be interposed between the lower electrode 20 and the electrolyte layer 40. The porous layer 30 may comprise a porous metal oxide. For example, referring to Figure IB, the porous layer 30 may comprise titanium dioxide (TiO2, 32). Alternatively, the porous layer 30 may include ZnO, indium tin oxide (ITO), fluorinated tin oxide (FTO), SnO2, antimony-doped SnO2, and the like. The porous layer 30 may be a coating layer coated on the lower electrode 20. The thickness of the porous layer 30 may be between about 100 nm and about 50 um. In one example, the thickness of the porous layer 30 may be between about 500 nm and about 10 um. The porous layer 30 may be composed of particles having a size within about 1 nm to about 1000 nm. As an example, the porous layer 30 may be composed of particles having a size within about 1 nm to about 100 nm. The porous layer 30 can be prepared by various methods such as spin coating, slot die coating, or bar coating. The porous layer 30 may be manufactured through a post-coating heat treatment process, and the heat treatment process may be performed at a temperature within a range of room temperature to about 1000 ° C, but is not limited thereto. The porous layer 30 may be formed on the upper electrode 60 or on the upper and lower electrodes 60 and 20 ). ≪ / RTI >

The electrolyte layer 40 may be interposed between the porous layer 30 and the electrochromic layer 50. The electrolyte layer 40 may be in a liquid, gel, or solid state. The electrolyte layer 40 may include a first electrochromic material and a compound electrolyte layer. The first electrochromic material includes an organic molecule, and the compound electrolyte layer may include a hydrogen ion (H +) or a lithium ion (Li +). As an example, the electrolyte layer 40 may include phenothiazine as a first electrochromic material and LiCO ₄ as a compound electrolyte layer. Alternatively, the first electrochromic material may be selected from the group consisting of triarylamine, triphenylamine, triarylamine derivatives, triphenylamine derivatives, phenazine, phenothiazine, ) Derivative, and a phenazine derivative. The electrolyte layer 40 can transfer ions between the porous layer 30 and the electrochromic layer 50. Further, the electrolyte layer 40 includes the first electrochromic material, and can participate in the discoloration reaction. This will be described later together with the electrochromic layer 50. The concentration of the first electrochromic material may range from about 0.1 to 50% (w / w). For example, the concentration of the first electrochromic material may range from about 1 to 10% (w / w). The solvent of the electrolyte may be an organic molecule containing propylene carbonate.

The electrochromic layer 50 may be disposed under the upper electrode 60. The electrochromic layer 50 may be interposed between the upper electrode 60 and the electrolyte layer 40. The electrochromic layer 50 may be opposed to the porous layer 30. In other words, the porous layer 30 is disposed between the electrolyte layer 40 and one of the upper and lower electrodes 60 and 20, and the electrolyte layer 40 and the upper and lower electrodes 60 and 20 The electrochromic layer 50 may be disposed between the other electrodes. The electrochromic layer 50 may comprise a second electrochromic material. The second electrochromic material may comprise an inorganic molecule. In one example, the second electrochromic material may comprise tungsten oxide (WOx). The thickness of the tungsten oxide may be between about 10 nm and 20,000 nm. For example, the thickness of the tungsten oxide may range from about 50 nm to 500 nm. The tungsten oxide may be prepared by a dry method (e.g., vacuum deposition) or by a wet method (e.g., sol-gel method).

As described above, the porous layer 30 may include a first electrochromic material, and the electrochromic layer 50 may include second electrochromic materials. The first and second electrochromic materials cause electrochromism by an oxidation / reduction process due to the injection and desorption of electrons and ions. At this time, the porous layer 30 and the electrochromic layer 50 can perform mutual reactions corresponding to each other. For example, the porous layer 30 may be an ion storage layer, the electrolyte layer 40 may be an ion transport path and an oxidative discoloration electrode layer, and the electrochromic layer 50 may be a reduced discoloration electrode layer. However, the present invention is not limited thereto, and the porous layer 30 may be a reduced color change electrode layer and the electrochromic layer 50 may be an oxidative discoloration electrode layer. Hydrogen ions (H +) or lithium ions (Li +) contained in the electrolyte layer 40 or the lithium ions (Li +) contained in the porous layer 30 and the electrochromic layer 50 are mixed with each other depending on the voltage applied to the upper and lower electrodes 20, As shown in FIG. At this time, the oxidation number of the porous layer 30 and the electrochromic layer 50 are changed so as to satisfy the charge neutral condition in the compound, and the optical characteristics (for example, the optical properties of the porous layer 30 and the electrochromic layer 50) For example, color, transparency) changes.

The barrier ribs 80 may be combined with the upper and lower electrodes 20 and 60 to couple the upper and lower electrodes 20 and 60 and the electrolyte layer 40 separated from each other. For example, as shown in FIG. 1A, the barrier ribs 80 may be provided to surround the side surfaces of the electrolyte layer 40.

FIGS. 2A and 2B are diagrams showing the electrochromic characteristics of the electrochromic device 1 of FIG. 1A. More specifically, FIG. 2A is a view showing when the electrochromic materials of the electrochromic device 1 are decolorized, and FIG. 2B is a view showing when the electrochromic materials of the electrochromic device 1 are colored.

Referring to FIG. 2A, when the first driving voltage is applied to the electrochromic device 1, both the electrolyte layer 40 including the electrochromic materials and the electrochromic layer 50 are decolored, To indicate a transparent state. In one example, the first drive voltage may be about -3V to 3V. At this time, the phenothiazine of the electrolyte layer 40 is reduced and the tungsten oxide (WOx) of the electrochromic layer 50 can be oxidized. The electrolyte layer 40 including reduced phenothiazine and the electrochromic layer 50 including oxidized tungsten oxide WOx may all be transparent. 2B, when the second driving voltage is applied to the electrochromic device 1, both the electrolyte layer 40 including the electrochromic materials and the electrochromic layer 50 are colored and applied from the outside It is possible to indicate a blocking state for blocking light. In one example, the second driving voltage may be a voltage of about -3V to 3V. At this time, the phenothiazine of the electrolyte layer 40 is oxidized and the tungsten oxide (WOx) of the electrochromic layer 50 can be reduced. The electrolyte layer 40 containing oxidized phenothiazine is reddish and the electrochromic layer 50 containing reduced tungsten oxide (WOx) may exhibit blue color. Thus, by controlling the applied voltage, coloring, decolorization, and transparency can be controlled.

3 is a cross-sectional view of the electrochromic device 2 according to one embodiment. The electrochromic device 2 includes a lower substrate 10, a lower electrode 20, a porous layer 30, an electrolyte layer 40, an electrochromic layer 50, an upper electrode 62, an upper substrate 70, And a sealant (80). For the electrochromic device 2, the same reference numerals as those of the electrochromic device 1 described with reference to Figs. 1A and 1B are provided with the same reference numerals, and redundant descriptions may be omitted for simplification of description have. The upper electrode 62 may include a first electrode layer 62a and a second electrode layer 62b stacked on each other. The first electrode layer 62a may be a mirror electrode, and the second electrode layer 62b may be a transparent electrode. For example, the first electrode layer 62a may include Ag, and the second electrode layer 62b may include ITO. Alternatively, the upper electrode 62 may be provided as a single mirror electrode. The lower electrode 20 may include ITO or FTO.

A general electrochromic device includes an electrolyte layer including a first electrochromic material, an electrochromic layer adjacent to the electrolyte layer and containing a second electrochromic material, an opposite electrode of a thin film adjacent to the electrolyte layer and facing the electrochromic layer And the electrochromic device having such a structure will hereinafter be referred to as a comparative example. In the electrochromic device according to the comparative example, incomplete discoloration occurs at the time of detachment / color switching, and the discoloration transmittance may be lowered. For example, when the electrolyte layer contains phenothiazine and the electrochromic layer contains tungsten oxide (WOx), it may be discolored incompletely upon discoloration after coloring, resulting in a red color rather than a transparent color . However, the electrochromic devices (1, 2) according to an embodiment of the present invention include a porous layer on the counter electrode facing the electrochromic layer so that the surface layer to the surface layer of the porous layer in contact with the electrolyte layer volume ratio can be increased. Thus, the redox reaction of the first electrochromic material of the electrolyte layer can be promoted and the decolorization transmittance can be increased. Hereinafter, a supplementary explanation will be given with reference to FIG. 4 and FIG.

FIG. 4 is a graph showing a reflection spectrum according to a comparative example, and FIG. 5 is a graph showing a reflection spectrum using the electrochromic device 2 of FIG. 4 shows the reflectance at the time of decolorization according to the comparative example, and (2) shows the reflectance at the time of coloring according to the comparative example. 5 'is the reflectance at the time of decolorization according to an embodiment of the present invention, and 2' is the reflectance at the time of coloring according to an embodiment of the present invention. The first driving voltage in FIGS. 4 and 5, that is, the driving voltage at the time of decoloring may be 0V, and the second driving voltage, that is, the driving voltage at the time of coloring, may be about -1.0V. 4 and 5, the reflectivities at the time of coloring according to the comparative examples and the present invention are substantially similar to each other (see (1) and (1) ') (See (2) and (2) '). As compared with FIG. 5, a phenomenon in which the reflectivity decreases in the section B of FIG. 4 occurs. And the section B may be about 480 nm to 530 nm. That is, according to the comparative example, it is confirmed that the electrochromic device absorbs the visible light of the green system when decolored, and the electrochromic device has a red color. On the other hand, according to one embodiment of the present invention, absorption of the visible light of the green system at the time of decolorization is prevented, and the discoloration transmittance is improved.

6 is a graph showing a transmission spectrum using the electrochromic device 1 of Fig. As described above, the upper electrode 60 and the lower electrode 20 of the electrochromic device 1 of Fig. 1 may be provided as transparent electrodes. 6 is the transmittance of the electrochromic device 1 when the electrochromic device 1 is discolored, and 4 is the transmittance of the electrochromic device 1 when the electrochromic device 1 is colored. The first driving voltage, that is, the driving voltage at the time of decoloring is 0 V, and the second driving voltage, that is, the driving voltage at the time of coloring, may be about -1.2 V. Referring to FIG. 6, in the transmittance at the time of decolorization, the spectral exfoliation does not occur in the section B. In other words, it can be seen that there is no afterimage of red color in the electrochromic device upon decolorization.

An electrochromic device according to embodiments of the present invention includes an electrolyte layer including a first electrochromic material, an electrochromic layer including an electrolyte layer and a second electrochromic material between one electrode, an electrolyte layer including an electrolyte layer and a second electrode A porous layer containing a porous metal oxide may be provided to prevent discoloration permeability loss and to remove discolored after-images. Alternatively, when the phenothiazine contained in the electrolyte layer is incompletely reduced, the electrochromic device may exhibit a decolorized after-image, for example, a red color of the electrochromic device. In addition, when the electrochromic device according to the embodiments of the present invention includes a mirror, the light reflectivity can be improved. 4 to 6, it can be seen that the present invention can be applied to both the transmission type electrochromic device and the reflection type electrochromic device.

In the above embodiments, the electrochromic devices are described as including the upper / lower substrates and the upper / lower electrodes. However, the upper / lower division is not limited to the structure and the shape of the embodiments of the present invention But is not limited thereto.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood. It is therefore to be understood that the above-described embodiments are illustrative and not restrictive in every respect.

Claims (9)

A first electrode;
A second electrode facing the first electrode;
An electrolyte layer interposed between the first and second electrodes, the electrolyte layer including an electrochromic material; And
And a porous layer interposed between at least one of the first and second electrodes and the electrolyte layer.
The method according to claim 1,
Wherein the porous layer comprises a porous metal oxide.
The method according to claim 1,
Wherein the electrochromic material of the electrolyte layer is phenothiazine. The method according to claim 1,
Wherein the porous layer comprises at least one of TiO2 (Titanium dioxide) and ITO (indium tin oxide).
The method according to claim 1,
Wherein the porous layer comprises at least one of fluorinated tin oxide (FTO), ZnO, SnO2, and antimony-doped tin oxide.
The method according to claim 1,
Further comprising an electrochromic layer,
Wherein the porous layer is interposed between any one of the first and second electrodes and the electrolyte layer,
Wherein the electrochromic layer is sandwiched between the other one of the first and second electrodes and the electrolyte layer.
The method according to claim 6,
Wherein the electrochromic layer comprises tungsten oxide.
A first electrode and a photochromic layer on the first electrode;
A second electrode facing the first electrode and a coating layer on the second electrode; And
And an electrolyte layer interposed between the electrochromic layer and the coating layer,
Wherein the electrolyte layer comprises a first electrochromic material, the electrochromic layer comprises a second electrochromic material, and the coating layer comprises a porous metal oxide.
9. The method of claim 8,
Wherein the first electrochromic material comprises an organic discoloring material,
Wherein the second electrochromic material comprises an inorganic discoloring material.

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