KR102010733B1

KR102010733B1 - Electrochromic device

Info

Publication number: KR102010733B1
Application number: KR1020160024593A
Authority: KR
Inventors: 김용찬; 김기환; 김수진
Original assignee: 주식회사 엘지화학
Priority date: 2016-02-29
Filing date: 2016-02-29
Publication date: 2019-08-14
Also published as: KR20170101702A

Abstract

The present application relates to an electrochromic device and a method of manufacturing the electrochromic device. The present application may provide an electrochromic device having improved electrochromic speed and durability, and a manufacturing method of the color fading device. The electrochromic device may be usefully used in various devices such as smart windows, smart mirrors, displays, electronic papers, active camouflages, and the like.

Description

Electrochromic Device

The present application relates to an electrochromic device and its use.

Electrochromism refers to a phenomenon in which optical properties such as color or transmittance of an electrochromic material change depending on an electrochemical oxidation and a reduction reaction. Electrochromic materials reversibly change the optical properties of materials, for example their inherent color and transmittance, depending on the movement, oxidation and reduction of electrons when a voltage is applied from the outside.

The electrochromic device may be composed of a working electrode, a counter electrode, and an electrolyte in a battery-like structure. As the electrochromic material, for example, an inorganic electrochromic material such as a metal oxide may be used. The inorganic electrochromic material may be formed in the form of a film on a transparent conductive electrode, such as ITO or FTO glass, to observe its properties and to make up the device. For example, ions such as Li ⁺ or Na ⁺ move, and at the same time electrons move through an external circuit to change the electron density of the electrochromic material and thereby change its optical properties. That is, when the insertion and extraction of electrons and ions occur by electrochemical oxidation and reduction reactions, coloration or decolorization occurs on the surface of the metal oxide.

The electrochromic device can be manufactured in a large area device at low cost, and has a low power consumption, and thus can be used in various fields such as smart windows, smart mirrors, and electronic paper. However, the electrochromic device has a disadvantage in that the discoloration speed is slow, and this disadvantage may be particularly limited to large area of the electrochromic device. In order to improve this disadvantage, various attempts have been made to lower the sheet resistance value of the transparent conductive electrode serving as the current collector of the electrochromic device.

Patent Document 1: Korean Patent Publication No. 2008-0051280

The problem to be solved by the present application is to provide an electrochromic device having excellent electrochromic speed and durability and its use.

The present application relates to an electrochromic device. The electrochromic device of the present application may sequentially include a first substrate, a first electrode layer, an electrochromic layer, an electrolyte layer, an ion storage layer, a second electrode layer, and a second substrate. In the present application, one or more electrode layers of the first electrode layer and the second electrode layer may be a composite electrode layer sequentially including a first metal oxide layer, a metal layer, and a second oxide layer. The electrochromic device of the present application may include a conductive barrier layer on one surface of the second metal oxide layer. Such electrochromic devices can have excellent electrochromic speed and durability.

1 exemplarily shows an electrochromic device according to an embodiment of the present application. 1 exemplarily illustrates in particular the case where the first electrode layer is a composite electrode layer. The electrochromic device illustrated in FIG. 1 includes a first substrate 10, a first electrode layer 11, an electrochromic layer 12, an electrolyte layer 20, an ion storage layer 32, and a second electrode layer 31. ) And a second substrate 30 in sequence, and the first electrode layer 11 sequentially includes a first metal oxide layer 11a, a metal layer 11b, and a second metal oxide layer 11c. And a conductive barrier layer 40 on one surface of the second metal oxide layer 103.

Hereinafter, the electrochromic device of the present application will be described in detail.

[Board]

The electrochromic device may comprise a first and a second substrate. The electrochromic device may include first and second substrates in opposing positions, wherein the first electrode layer, the electrochromic layer, the electrolyte layer, the ion storage layer, and the first substrate are disposed between the opposing first and second substrates. Two electrode layers may be provided sequentially.

The first and second substrates may be glass substrates or polymer substrates, respectively. Specifically, the first and second substrates may be any one selected from the group consisting of glass, glass fiber, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, polyimide, and combinations thereof. According to an embodiment of the present application, the first substrate may be a glass substrate and the second substrate may be a polymer substrate. When the second substrate is a polymer substrate, the thickness may be appropriately selected in consideration of the purpose of the present application. The thickness of the polymer substrate may be, for example, 10 μm to 300 μm, more specifically 150 μm to 250 μm.

[Electrode layer]

The electrochromic device may comprise a first electrode layer and a second electrode layer. The first electrode layer may be formed on the first substrate, and the second electrode layer may be formed on the second substrate. The electrochromic device may include a first electrode layer and a second electrode layer in a state in which the first electrode layer and the second electrode layer are disposed to face each other. It may be provided as.

The first and second electrode layers may perform a function of supplying charge to the electrochromic layer or the ion storage layer. The first electrode layer may be referred to as an electrode, for example an active electrode, which has an electrochromic action in the electrochromic device adjacent to the electrochromic layer. The second electrode layer may be referred to as an electrode, for example, a counter electrode, capable of receiving hydrogen or lithium ions desorbed from the active electrode adjacent to the ion storage layer. However, as will be described later, when the ion storage layer also includes an electrochromic material, both the first electrode layer and the second electrode layer may be active electrodes and function as counter electrodes.

At least one of the first electrode layer and the second electrode layer may be a composite electrode layer sequentially including a first metal oxide layer, a metal layer, and a second oxide layer. Only one electrode layer of either the first electrode layer or the second electrode layer may be a composite electrode layer, or both the first electrode layer and the second electrode layer may be a composite electrode layer. The first metal oxide layer may be adjacent to the first and / or second substrate as compared to the second metal oxide layer. Such a composite electrode layer can realize high visible light transmittance and low sheet resistance when the optical constant is properly adjusted.

The composite electrode layer may have a visible light transmittance of about 80% or more. As used herein, visible light may mean light having a wavelength of about 380 nm to 700 mm. Since the composite electrode layer may exhibit excellent transparency, it may be suitable for implementing an electrochromic device by replacing the transparent conductive oxide which is a material of the conventional electrode layer.

The composite electrode layer may have a sheet resistance of 10 Ω / sq or less. Since the composite electrode layer has a low sheet resistance value, it is possible to provide an electrochromic device having an improved electrochromic speed. Specifically, the coloration and decolorization conversion time of the electrochromic device can be reduced.

The composite electrode layer having the visible light transmittance and the sheet resistance may be implemented by organically controlling the refractive index and the thickness of the first metal oxide layer, the metal layer, and the second oxide layer.

The refractive index for light of 550 nm wavelength of the first metal oxide layer can be, for example, 1.8 to 2.8, more specifically 2.0 to 2.5. Alternatively, the refractive index of light of 370 nm wavelength of the first metal oxide layer may be 2.0 to 3.2. The thickness of the first metal oxide layer can be, for example, 20 nm to 60 nm, more specifically 20 nm to 50 nm, 20 nm to 40 nm. The first metal oxide layer may be made of a suitable material to exhibit the refractive index in the thickness range. For example, the first metal oxide layer may include niobium (Nb) oxide, cesium (Ce) oxide, or indium doped tin oxide (ITO).

The refractive index of the metal layer with respect to light of 550 nm wavelength may be, for example, less than 0.5, more specifically 0.4 or less, 0.3 or less, or 0.2 or less. The thickness of the metal layer can be for example 5 nm to 20 nm, more specifically 10 nm to 15 nm. The metal layer may be made of a suitable material to exhibit the refractive index in the thickness range. For example, the metal layer may include silver (Ag) or an alloy of silver (Ag). The alloy metal with silver may be, for example, copper (Cu), palladium (Pd), nickel (Ni), zinc (Zn), or the like.

The refractive index for the light of 550 nm wavelength of the second metal oxide layer can be for example 1.5 to 2.5, more specifically 1.7 to 2.3 and 1.9 to 2.1. The thickness of the second metal oxide layer may for example be 30 nm to 70 nm or 40 nm to 60 nm, more specifically 20 nm to 80 nm. The second metal oxide layer may be made of a suitable material to exhibit the refractive index in the thickness range. For example, the bimetallic oxide layer may be formed of aluminum zinc oxide (AZO), gallium doped zinc oxide (GZO), indium tin oxide (ITO) or niobium (Nb) oxide. It may include.

In the composite electrode layer, the refractive index of the first metal oxide layer may be higher than that of the second metal oxide layer, and the refractive index of the metal layer may be lower than that of the second metal oxide layer. In this refractive index relationship, it may be more advantageous to realize excellent visible light transmittance and low sheet resistance.

The composite electrode layer may be formed through a thin film deposition process. As the thin film deposition process, for example, a vacuum deposition process such as a sputter may be exemplified, but is not limited thereto.

When only one electrode layer of the first electrode layer and the second electrode layer is the composite electrode layer, the other electrode layer may be a single layer electrode layer including a conductive material. As one example, the first electrode layer may be a composite electrode layer and the second electrode layer may be a single layer electrode layer comprising a conductive material.

Examples of the conductive material may include a transparent conductive oxide (TCO), a conductive polymer, a silver nano wire, a metal mesh, or the like. Examples of the transparent conductive oxide include indium tin oxide (ITO), fluor doped tin oxide (FTO), aluminum doped zinc oxide (AZO), gallium doped zinc oxide (GZO), antimony doped tin oxide (ATO) and indium (IZO) doped Zinc Oxide), Niobium doped Titanium Oxide (NTO), ZnO, or CTO may be exemplified, but is not limited thereto. The electrode layer may be manufactured by forming a conductive material in a thin film form on a substrate through a process such as sputtering or digital printing.

When the second electrode layer is a single layer electrode layer, the thickness may be appropriately selected in consideration of the purpose of the present application. The thickness of the electrode layer of a single layer may be for example 100 nm to 3000 nm, more specifically 150 nm to 250 nm.

The voltage applied to the first electrode layer and the second electrode layer through an external circuit can be appropriately adjusted within a range that does not impair the object of the present application. The higher the voltage applied, the better the characteristics of the electrochromic device, but the durability may be degraded by accelerating deterioration of the device. In view of this, it is possible to appropriately adjust the external voltage applied to the first electrode layer and the second electrode layer. For example, the voltage applied to the first or second electrode layer through an external circuit may be -5 V to +5 V, more specifically -2 V to +2 V, but is not limited thereto. In addition, the voltages at the time of coloring and decoloring may be the same or different, which may be appropriately adjusted as necessary. The voltage may be applied by an AC power source, and a power supply device or a method of applying the voltage may be appropriately selected by those skilled in the art.

[Conductive barrier layer]

The electrochromic device may include a conductive barrier layer provided on one surface of the second metal oxide layer. If the first electrode layer is a composite electrode layer, a conductive barrier layer may be provided between the second metal oxide layer and the electrochromic layer. The conductive barrier layer may be provided between the second metal oxide layer and the ion storage layer when the second electrode layer is a composite electrode layer.

The electrochromic device of the present application can secure excellent durability through the conductive barrier layer. Specifically, when the electrolyte layer is driven above a specific potential, ionization may proceed to the metal of the composite electrode layer due to the penetration of ions, for example, lithium ions, included in the electrolyte storage layer and the electrolyte layer. There is a problem that deterioration occurs by etching. According to the present application it is possible to prevent the penetration of ions by providing a conductive barrier layer between the composite electrode layer and the electrolyte layer, thereby preventing the degradation of the composite electrode layer even within a specific reaction potential to improve the durability of the electrochromic device. .

The thickness of the conductive barrier layer may be appropriately selected in consideration of the purpose of the present application. The thickness of the conductive barrier layer can be, for example, 100 nm to 500 nm, more specifically 200 nm to 300 nm. The conductive barrier layer can include a conductive material. Examples of the conductive material may include a transparent conductive oxide (TCO). As the transparent conductive oxide, for example, indium doped tin oxide (ITO), fluoro zinc oxide (FTO), aluminum zinc oxide (AZO), aluminum doped zinc oxide (AZO), gallium zinc oxide (GZO; Galium doped Zinc Oxide), Antimony doped Tin Oxide (ATO), Indium doped Zinc Oxide (IZO), Niobium Titanium Oxide (NTO), Cadmium Zinc Doped (CTO) Zinc Oxide) or Zinc Oxide may be exemplified, but is not limited thereto.

[Electrochromic layer]

The electrochromic layer may comprise an electrochromic material. Electrochromism is a phenomenon in which the color is reversibly changed in response to an electrical signal. Electrochromism may be caused by an insertion / extraction process of electrons and ions (H ⁺ , Li ^+, etc.) in the electrochromic material. Electrochromic materials can be classified into reducing electrochromic materials that are reversibly colored by ion insertion and oxidative electrochromic materials that are reversibly colored by ion extraction.

As the electrochromic material, a metal oxide electrochromic material, a metal complex compound, an organic electrochromic material, or a conductive polymer electrochromic material may be used.

Examples of metal oxide electrochromic materials include tungsten (W), titanium (Ti), vanadium (V), molybdenum (Mo), niobium (Nb), chromium (Cr), manganese (Mn), tantalum (Ta), One or more of metal oxides of iron (Fe), nickel (Ni), cobalt (Co), iridium (Ir), and lithium nickel (LiNi) may be used. Metal oxides such as tungsten (W), titanium (Ti), vanadium (V), molybdenum (Mo), and niobium (Nb) may be classified as reducing electrochromic materials, and vanadium (V), chromium (Cr), and manganese. (Mn), tantalum (Ta), iron (Fe), nickel (Ni), cobalt (Co), iridium (Ir) or lithium nickel (LiNi) may be classified as an electrochromic material.

As the metal complex, for example, Prussian blue, Phthalocyanines or Bismuth may be used.

As the organic electrochromic material, for example, viologen or quinone may be used.

Examples of the conductive polymer electrochromic material include polythiophene, polyaniline, polypyrrole, polyanthracene, polyfluorene, polycarbazole, polyphenylene One or more of polyphenylenevinylene and derivatives thereof can be used.

The thickness of the electrochromic layer may be appropriately selected in view of the purpose of the present application. The thickness of the electrochromic layer can be for example 100 nm to 500 nm, more specifically 200 nm to 400 nm.

[Ion storage layer]

The ion storage layer may serve to receive and recharge the charge of ions necessary to cause the electrochromic layer to discolor. Thus, in order to balance the charge balance between the ion storage layer and the electrochromic layer, the ion storage layer may comprise a conductive material complementary to the electrochromic layer.

The ion storage layer may comprise an oxidative conductive material when the composite electrochromic layer comprises a reducing electrochromic material. Alternatively, the ion storage layer may comprise a reducing conductive material when the composite electrochromic layer comprises an oxidizing electrochromic material.

As one example, the conductive material included in the ion storage layer may be an electrochromic material. The ion storage layer may comprise an oxidizing electrochromic material when the composite electrochromic layer comprises a reducing electrochromic material, and the ion storage layer includes a reducing electrochromic material when the composite electrochromic layer comprises a reducing electrochromic material. can do. According to one embodiment of the present application, when tungsten oxide (WO ₃ ) is used in the composite electrochromic layer, lithium nickel oxide (LiNiO _x ) may be used in the ion storage layer.

Alternatively, the ion storage layer may comprise a suitable conductive material, for example conductive material such as conductive graphite, regardless of whether the composite electrochromic layer comprises a reducing color change material or an oxidizing color change material.

The thickness of the ion storage layer may be appropriately selected within a range that does not impair the purpose of the present application. For example, the thickness of the ion storage layer may be 50 nm to 300 nm, more specifically 150 nm to 250 nm. When the thickness of the ion storage layer satisfies the above range, it is possible to provide an electrochromic device having improved electrochromic speed and durability.

[Electrolyte layer]

The electrolyte layer may comprise an electrolyte salt. Specifically, the electrolyte layer may be any one selected from the group consisting of a liquid electrolyte, a gel electrolyte, a solid electrolyte, a polymer electrolyte, and a gel polymer electrolyte in which an electrolyte salt is dissolved, and in the case of a liquid electrolyte, an electrolyte salt may be dissolved in a solvent. have. According to one embodiment of the present application, the electrolyte may be a gel polymer electrolyte.

The electrolyte salt may be an organic electrolyte salt or an inorganic electrolyte salt. More specifically, the electrolyte salt may include a lithium salt, potassium salt, sodium salt or ammonium salt, for example, the electrolyte salt is n-Bu ₄ NClO ₄ , n-Bu ₄ NPF ₆ , NaBF ₄ , LiClO ₄ , Any one selected from the group consisting of LiPF ₆ , LiBF ₄ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , C ₂ F ₆ LiNO ₄ S ₂ , K ₄ Fe (CN) _6, and combinations thereof Can be.

The solvent may be applied as long as it is a non-aqueous solvent, and specifically, dichloromethane, chloroform, acetonitrile, ethylene carbonate (EC), propylene carbonate (PC), tetrahydrofuran (THF), butylene carbonate, and combinations thereof. It may be any one selected from the group consisting of.

The thickness of the electrolyte layer may be appropriately selected within a range that does not impair the purpose of the present application. For example, the thickness of the electrolyte layer may be 50 nm to 300 nm, more specifically 150 nm to 250 nm. When the thickness of the electrolyte layer satisfies the above range, it is possible to provide an electrochromic device having improved electrochromic speed and durability.

The electrochromic device of the present application can be manufactured by stacking the above-described layers. The lamination of each layer can be made by appropriately selecting a known lamination method. For example, the lamination method may be sputtering, sol-gel, e-beam evaporation, pulsed laser deposition, chemical vapor deposition, spin coating, or spin coating. ) Or dip coating may be exemplified.

The electrochromic device of the present application may have excellent electrochromic speed and durability. Such electrochromic devices may be usefully used in various devices such as smart windows, smart mirrors, displays, electronic paper, and active camouflage. The manner of configuring such a device is not particularly limited and a conventional manner may be applied as long as the electrochromic yarn of the present application is applied.

The present application can provide an electrochromic device having improved electrochromic speed and durability. Such electrochromic devices may be usefully used in various devices such as smart windows, smart mirrors, displays, electronic paper, and active camouflage.

1 is a schematic diagram of an electrochromic device of an embodiment of the present application.
2 is a schematic view of an electrochromic device of Comparative Example 1. FIG.
3 is a schematic view of an electrochromic device of Comparative Example 2. FIG.
4 is a time-current graph of Comparative Example 1. FIG.
5 is a time-current graph of Example 1. FIG.
6 is a time-current graph of Comparative Example 2. FIG.
7 is a schematic diagram of the device of Reference Example 1. FIG.
8 is an XPS Depth Profile analysis result when depositing a LiNiOx layer.
9 is an XPS Depth Profile analysis result when coloring the LiNiOx layer.
10 is an XPS Depth Profile analysis result when decolorization of the LiNiOx layer.

Hereinafter, the contents of the present application will be described in more detail with reference to Examples and Comparative Examples, but the scope of the present application is not limited to the following contents.

Example One

WO ₃ Preparation of the electrode

Niobium oxide (NbOx) layer (thickness: about 30 nm), silver (Ag) layer (thickness: about 12 nm) and aluminum zinc oxide (AZO) layer (thickness: about 50 nm) using a DC sputter on a glass substrate Were deposited sequentially to produce a composite electrode layer. Next, an indium tin oxide (ITO) layer (thickness: about 300 nm) was deposited on the zinc aluminum oxide (AZO) layer as a conductive barrier layer using a DC sputter. Next, a working electrode was prepared by depositing a tungsten oxide (WO ₃ ) layer (thickness: about 230 nm) as an electrochromic layer using a DC sputter on an indium tin oxide layer.

LiNiOx Preparation of the electrode

Deposit an ITO layer (thickness: about 200 nm) as an electrode layer using a DC sputter on a PET film (thickness: about 188 μm), and use nickel lithium oxide (Ion storage layer) as an ion storage layer using a DC sputter on the ITO layer. A counter electrode was prepared by depositing a LiNiOx) layer (thickness: about 200 nm).

Preparation of Electrochromic Device

PC (propylene carbonate) and LiClO ₄ Using a gel polymer electrolyte comprising a mixture of, an electrochromic device was fabricated by bonding the working electrode and the counter electrode so that the ITO layer of the WO ₃ electrode and the LiNiOx layer of the LiNiOx electrode contacted the gel polymer electrolyte. 1 is a schematic diagram of an electrochromic device according to a first embodiment.

Comparative example One

In fabricating the WO ₃ electrode in Example 1, electrochromic in the same manner as in Example 1 except that the composite electrode layer and the conductive barrier layer were not deposited but instead an ITO layer (thickness about 200 nm) was deposited. The device was manufactured. 2 is a schematic view of an electrochromic device according to Comparative Example 1. FIG.

Comparative example 2

In preparing the WO ₃ electrode in Example 1, an electrochromic device was manufactured in the same manner as in Example 1 except that no conductive barrier layer (ITO layer) was deposited. 3 is a schematic view of an electrochromic device according to Comparative Example 2. FIG.

Evaluation of Electrochemical Properties of Electrochromic Devices 1

The electrochemical characteristics of Example 1 and Comparative Example 1 were evaluated by Potentialiostat using Potential-step chrono amperometry (PSCA). As the electrolyte, a solution of 1 mol of LiClO ₄ in propylene carbonate (PC) solvent was used. The working electrode used the WO ₃ electrode of Example 1 and Comparative Example 1, the counter electrode used Pt, and the reference electrode used Ag wire. The specimen size of the working electrode was prepared as width x length = 2 cm x 3 cm.

In the PSCA method, a constant voltage is applied in one direction at a constant speed, and then the direction is repeatedly changed. At this time, a current is measured over time corresponding to the voltage applied to the working electrode. When an external potential is applied, an electrolytic current flows, which decreases with time and becomes zero after a long time. The PSCA method measures current-time obtained by such a potential step. The PSCA of the WO3 electrode was repeated 100 times in the recoding step 1 sec rate in the -1.0V ~ 1.0V section to measure the current. 4 and 5 show the results of time-current graphs measured by the PSCA method for the WO ₃ electrodes of Comparative Example 1 and Example 1, respectively. Based on the graph, the coloring and discoloring peak currents and charge amounts are calculated. The electrochromic characteristic evaluation is carried out in Constant Voltage Mode, and as shown in FIGS. 4 and 5, a graph is formed in which the amount of current flowing instantaneously when a constant potential is applied is taken and then decreased. The maximum current at this time is called the peak current. Coloring and decolorizing times were calculated based on the amount of 80% current compared to the peak current. The peak current is inversely proportional to the sheet resistance value of the electrode layer serving as the current collector and tends to increase in proportion to the lithium ion diffusion coefficient value of the electrochromic material.

Table 1 shows the results of measuring the optical properties based on the electrochemical reaction of the three-electrode cell. The sheet resistance was measured by the contact method using a 4 point prove device, the peak current was measured by the CV (Constant Voltage) mode method using the Potentiostat, and the transmittance was measured by the UV-vis spectrometer device (Solidspec 3700). The coloration time was measured by using a Potentiostat to determine the peak current level of 80%.

Driving Bias: -2 to +2 V

Duration Time: 50s (colored)-50s (discolored)

Comparative Example 1
(ITO electrode layer) Example 1
(Composite electrode layer) Sheet Resistance (ohm / sq) 15 5 Peak current (mA) 5 7.5 Permeability in coloring (%) 39 1.7 Permeability at bleaching (%) 80 60 Transmittance Difference (%) 41 43 Coloring time (seconds) 10 6.5

4, 5 and Table 1, it can be seen that in Example 1, the peak current is increased compared to Comparative Example 1, and the coloring time decreases according to the low surface resistance characteristics.

Evaluation of Electrochemical Properties of Electrochromic Devices 2

The electrochemical properties of Example 1 and Comparative Example 2 were evaluated by potential-step chrono amperometry PSCA using Potentiostat. Except for using the WO ₃ electrodes of Example 1 and Comparative Example 2 as working electrodes, respectively, the same conditions as in Evaluation 1 were performed, and the results are shown in FIGS. 5 (Example 1) and 6 (Comparative Example 2). Therefore, the degradation (degradation) was evaluated accordingly.

Referring to FIG. 6, it can be seen that in Comparative Example 2 in which the conductive barrier layer is not provided, the amount of charge is reduced after about 10 cycles, so that deterioration occurs during the initial activation. In Comparative Example 1, deterioration occurred after 10 cycles even when a voltage of ± 1.0 V was applied.

In contrast, referring to FIG. 5, Example 1 provided with a conductive barrier layer completed activation after 5 cycles, and showed durability of driving for 10000 sec without reducing charge amount.

Reference Example One LiNiOx Preparation of the electrode

Indium tin oxide (ITO) layer (thickness: about 32 nm), silver (Ag) layer (thickness: about 12 nm) and indium tin oxide (ITO) layer (thickness: about 30 ~) using DC sputter on the glass substrate 40 nm) was sequentially deposited to produce a composite electrode layer. Next, a lithium nickel oxide (LiNiOx) layer (thickness: about 100 nm) was deposited on an indium tin oxide (ITO) layer (thickness: about 30-40 nm) using a DC sputter to prepare a LiNiOx electrode. 7 is a schematic diagram of a device according to Reference Example 1. FIG.

Evaluation of Electrochemical Properties of Electrochromic Devices 3

Electrochemical properties of Reference Example 1 were measured by Potentiostat. As working electrode of Reference Example 1 The same conditions as in Evaluation 1 were conducted except that LiNiOx electrodes were used. In the direction of lithium nickel oxide (LiNiOx), which is an electrochromic layer, it is colored when -1V is applied, and when it is + 1V, it is discolored. 8 to 10 show the results of XPS Depth Profile analysis during deposition (sample 1), coloring (sample 2) and decolorization (sample 3) of lithium nickel oxide (LiNiOx) layers, respectively.

8 to 10, it can be seen that the Li content in FIGS. 9 and 10 was reduced compared to FIG. 8, through which Li ions included in the lithium nickel oxide (LiNiOx) layer penetrated into the electrode layer. . As shown in the schematic diagram of FIG. 7, when Li ions penetrate into the electrode layer, Li precipitation occurs in combination with the electron and may grow in the form of dendrites. It is presumed that the etching reaction of the metal layer occurs due to this chemical reaction, which causes deterioration and durability degradation of Comparative Example 2 of Evaluation 2.

10: first substrate
11: first electrode layer
12: electrochromic layer
20: electrolyte layer
32: ion storage layer
31: second electrode layer
32: second substrate
40: conductive barrier layer
11a: first metal oxide layer
11b: metal layer
11c: second metal oxide layer
11 ': ITO electrode layer

Claims

Sequentially comprising a first substrate, a first electrode layer, an electrochromic layer, an electrolyte layer, an ion storage layer, a second electrode layer, and a second substrate, wherein at least one of the first and second electrode layers A composite electrode layer sequentially comprising a first metal oxide layer, a metal layer, and a second metal oxide layer, wherein one surface of the second metal oxide layer includes a conductive barrier layer, and the composite electrode layer has a sheet resistance of 10 Ω / up to sq, the conductive barrier layer is between the second metal oxide layer and the electrochromic layer.

The method of claim 1,
The composite electrode layer is an electrochromic device having an average visible light transmittance of 80% or more.

delete

The method of claim 1,
The first metal oxide layer has a refractive index of 1.8 to 2.8 for light of 550 nm wavelength electrochromic device.

The method of claim 1,
The electrochromic device having a thickness of the first metal oxide layer is 20 nm to 40 nm.

The method of claim 1,
The first metal oxide layer includes niobium (Nb) oxide, cesium (Ce) oxide, or indium doped tin oxide (ITO).

The method of claim 1,
The metal layer is an electrochromic device having a refractive index of less than 0.5 for light of 550 nm wavelength.

The method of claim 1,
Electrochromic device, the metal layer is 5 nm to 20 nm thick.

The method of claim 1,
Electrochromic device wherein the metal layer comprises silver (Ag) or an alloy of silver (Ag).

The method of claim 1,
The second metal oxide layer has an electrochromic device having a refractive index of 1.5 to 2.5 for light of 550 nm wavelength.

The method of claim 1,
The second metal oxide layer has a thickness of 20 nm to 80 nm electrochromic device.

The method of claim 1,
The second metal oxide layer includes aluminum doped zinc oxide (AZO), gallium doped zinc oxide (GZO), indium doped tin oxide (ITO) or niobium (Nb) oxide. Electrochromic device.

The method of claim 1,
An electrochromic device, wherein the refractive index of the first metal oxide layer is higher than that of the second metal oxide layer, and the refractive index of the metal layer is lower than that of the second metal oxide layer.

delete

The method of claim 1,
An electrochromic device having a thickness of the conductive barrier layer of 100 nm to 500 nm.

The method of claim 1,
The conductive barrier layer may be formed of indium doped tin oxide (ITO), fluorine zinc oxide (FTO), aluminum zinc oxide (AZO), aluminum doped zinc oxide (AZO), gallium zinc oxide (GZO) ), Antimony doped Tin Oxide (ATO), Indium doped Zinc Oxide (IZO), Niobium doped Titanium Oxide (NTO), Cadmium Zinc Oxide (CTO) or Electrochromic device comprising zinc oxide (Zinc Oxide).

The method of claim 1,
An electrochromic device, wherein the first electrode layer is a composite electrode layer and the second electrode layer comprises a transparent conductive material.

The method of claim 1,
The electrochromic layer is an electrochromic device comprising a metal oxide electrochromic material, an organic electrochromic material or a conductive polymer electrochromic material.

The method of claim 1,
Electrochromic layers include tungsten (W), titanium (Ti), vanadium (V), molybdenum (Mo), niobium (Nb), chromium (Cr), manganese (Mn), tantalum (Ta), iron (Fe), nickel An electrochromic device comprising at least one metal oxide of (Ni), cobalt (Co), iridium (Ir), and lithium nickel (LiNi).

The method of claim 1,
The ion storage layer includes an oxidative conductive material when the electrochromic layer includes a reducing electrochromic material, or an electrochromic device comprising a reducing conductive material when the electrochromic layer includes an oxidizing electrochromic material.

The method of claim 1,
Electrolytic layer is an electrochromic device comprising an electrolyte salt.

Smart window comprising the electrochromic device of claim 1.