KR102066259B1 - An electrochromic device - Google Patents

Abstract

According to an embodiment of the present invention, provided is an electrochromic device in which a first electrode, an electrochromic layer, an electrolyte layer, and a second electrode are stacked, wherein the electrochromic layer is made of an organic material, and the thickness of the electrochromic layer is 5nm to 20μm.

Description

Electrochromic Device {AN ELECTROCHROMIC DEVICE}

The present invention relates to an electrochromic device, and more particularly, to an electrochromic device programmable according to a use.

Electrochromism device refers to a device that changes the color of the electrochromic material by an electric redox reaction according to the application of an electric field, thereby changing the light transmission characteristics, a typical electrochromic material is tungsten oxide. . Since then, the discoloration characteristics due to various organic / inorganic materials have been studied, and the development to apply it to a smart window (smart window) or display by making it as a device has been made continuously.

Meanwhile, an electrochemical capacitor (pseudocapacitor) refers to a device that stores electrical energy in the form of electrochemical energy by an electrical redox reaction and can be used when needed, and an electric double layer capacitor (Electric Double Capacitor) Compared with Layer Capacitor, it has higher energy density and power density.

The two devices have a similar structure, and are easy to combine, and at the same time, two functions such as change in transmittance and energy charge / discharge can be simultaneously achieved. In this case, the energy level is visually confirmed to the user, which is easy for the user. Can be used. The electrochromic capacitor may be properly programmed as an element that reacts autonomously by light, heat, electricity, and the like.

Recently, many studies on supercapacitors have been conducted to increase the slow charging and discharging speed of conventional batteries. Supercapacitors can be classified into two types. Among them, an electric double layer capacitor is a device that stores energy using an electric double layer phenomenon by using a material having good adsorption such as carbon. On the other hand, an electrochemical capacitor (pseudocapacitor) using a redox reaction of a material has a higher energy density than an electric double layer capacitor because it can store not only the energy by the electric double layer but also the charge by the redox. In addition, when the color of the material is changed during redox, the user can easily know the amount of energy storage by changing the color according to the amount of storage of electrical energy.

Accordingly, research on capacitors based on electrochromic materials has been conducted in various approaches.

Di Wei, et al, Nano Lett. 2012, 12, 1857-1862] achieved an energy density of 13.9 Wh / kg with electrochromic V ₂ O ₅ , yellow and negative when charged in the positive direction (+3.5 V) The color difference at the time of charging and discharging was light blue when charged with (-3.5V) and green when discharged, and maximum 40% or more (Vis region) was achieved. However, the Coulombic Efficiency was very low (<5%) and rapidly decreased to about 30% of the initial energy storage capacity in 10 charge / discharge tests.

Peihua Yang et al, Angew. Chem. Int. Ed. In 2014, 53, 11935-11939, WO ₃ fabricated a capacitor (type 1) in both electrochromic layers to produce a large area device of 15 cm * 15 cm, achieving an energy density of about 4 Wh / kg. However, since the color change existed outside the voltage range that can be charged and discharged, the effect of the electrochromic effect and the voltage range that can act as a capacitor are different and cannot be used at the same time. In order to compensate for this, polyaniline was coated on both ends, but specific energy density or color difference was not reported.

In Huige Wei, et al, Polymer 54 (2013) 1820-1831, polyaniline was combined with graphene oxide, and the same electrochromic layer was prepared. An energy storage density of 2.52 mWh / cm ² was achieved and a color difference of 60% at 633 nm was achieved. However, it was not manufactured with a capacitor, and stability was drastically decreased in the repeated experiments, and thus, the energy storage density of about 50% was maintained at the initial charge and discharge after 1,000 cycles.

As such, attempts have recently been made to electrochromic capacitors capable of visually confirming the amount of stored energy while storing energy and using it as necessary, but are still stable and have large color differences, and have high energy density. Electrochromic capacitors should be intensively studied for future electro-optical devices. In order to achieve this, it is necessary to improve the structure of the electrolyte, the electrochromic material and the electrode, and the success in this part can realize high stability, high energy density and large color difference, and thus it can be applied to various applications. It is expected.

The present invention is to solve the above-mentioned problems of the prior art, an object of the present invention is to use the complementary redox reaction of the electrochromic layer and the electroactive layer can store the electrical energy in the form of electrochemical energy, The transmittance is changed by the amount of stored energy to visually check the energy storage of the capacitor, and to provide an electrochromic device that can be used.

One aspect of the present invention, in the electrochromic device in which the first electrode, the electrochromic layer, the electrolyte layer and the second electrode is laminated, the electrochromic layer is made of an organic material, the thickness of the electrochromic layer is 5nm ~ 20 An electrochromic device having a thickness of µm is provided.

In one embodiment, the organic material may be a conductive polymer.

In one embodiment, the conductive polymer is polythiophene, polyaniline, polypyrrole, polyanthracene, polyanthracene, polyfluorene, polycarbazole, polyphenylene It may be one selected from the group consisting of vinylene (polyphenylenevinylene), polyacetylene, polyarylene, derivatives thereof, and combinations of two or more thereof.

In one embodiment, further comprising an electroactive layer between the electrolyte layer and the second electrode, the electroactive layer may be made of an inorganic material, an organic material, or a combination thereof.

In one embodiment, the thickness of the electroactive layer may be 500 ~ 5,000nm.

In one embodiment, the inorganic material may be one selected from the group consisting of metals, metal oxides, alloys thereof, polyoxometalate, and combinations of two or more thereof.

In one embodiment, the electrolyte layer may be a liquid electrolyte in which an electrolyte salt is dissolved, a gel electrolyte, a solid electrolyte, a polymer electrolyte, or a liquid electrolyte in which an electrolyte salt is melted.

In one embodiment, the electrolyte salt is a salt consisting of a cation and an anion, the cation is tetraammonium, magnesium, lithium, sodium, potassium, calcium, azole compound represented by Formula 1 or Formula 2 and combinations of two or more thereof one, and wherein the anion is selected from the group consisting of the _{^{BF 4 -, PF 6 -,}} N (CN) 2 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF _{^{-, (CF 3) 6 P}} -, (CF 3 CF 2 SO 2) 2 N -, (CF 3 SO 2) 2 N -, CF 3 SO 3 -, CF 3 CF 2 (CF 3) 2 CO -, _{(CF 3 SO 2) 2 CH} -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 -, CH 3 CO 2 -, thiocyanate, formate, Acetate, nitrate, perchlorate, sulfate, hydroxide, alkoxide, halide, carbonate, oxalate and combinations of two or more thereof.

<Formula 1>

<Formula 2>

In the above formula, R ₁ ~ R ₁₀ are each independently a hydrogen atom; halogen; An alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, an aryl group, a cycloalkyl group or a benzyl group which may be substituted with one or more NO ₂ or one or more OH; An alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, an allyl group, a cycloalkyl group or a benzyl group which may be substituted with one or more NH ₂ ; It is one selected from the group consisting of an alkyl group having 3 to 10 carbon atoms, alkenyl group, aryl group, allyl group, cycloalkyl group or benzyl group which may be substituted with one or more halogen.

In one embodiment, the liquid electrolyte is selected from the group consisting of polymethylmethacrylate (PMMA), polyethyleneoxide (PEO), polyvinylidene fluoride (PVDF), polyvinyllidene fluoride-co-hexafluoropropyle-ne (PVDF-HFP) and a combination of two or more thereof It may further include one.

In one embodiment, the electrochromic device may satisfy the following Equation 1.

<Equation 1>

A> 0.5 * B

In the above formula, A is the energy storage density of the electrochromic device after 10,000 charge and discharge, B is the energy storage density of the first electrochromic device.

In the electrochromic device according to an aspect of the present invention, the electrochromic layer is made of an organic material, and by controlling the thickness of the electrochromic layer to a certain range, the color difference is large and the color difference is large while storing a lot of energy. In addition, the amount of stored energy can be visually confirmed to have a user-friendly property. The electrochromic device manufactured as described above may be applied to various fields such as a display, a sensor, a capacitor, a battery, an e-book, an electronic paper, a rearview mirror, a portable computer, a solar control window, a decorative product, an electronic product, and the like.

It is to be understood that the effects of the present invention are not limited to the above effects, and include all effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic cross-sectional structure of an electrochromic device according to an embodiment of the present invention;
2 is a cyclic voltammogram (a) and a charge / discharge graph (b) of an electrochromic device manufactured according to Example 1 and Comparative Example 1 of the present invention;
3 is a potential analysis graph (a, b) of the electrochromic device prepared according to Example 2 and Comparative Example 2 of the present invention, the charge and discharge graph (c) of the device and the stability graph (d) of the change in transmittance;
4 is a charge / discharge graph (a), a cyclic voltammogram (b) and a transmittance change graph (c) of the electrochromic devices manufactured according to Example 3 and Comparative Example 3 of the present invention;
FIG. 5 is a photograph showing whether discoloration occurs during charging (1V, -1V) and discharging (0V) of the electrochromic device manufactured according to Example 2 of the present invention; FIG.
6 is a schematic diagram of a system using an electrochromic device according to an embodiment of the present invention;
7 is a circuit diagram of a system for autonomously adjusting the amount of incoming light by adjusting transparency according to the amount of external light using an optical sensor according to an embodiment of the present invention;
8 is a circuit diagram of a system capable of energy charging and discharging and changing color according to temperature using a temperature sensor;
9 is a photo of the electrochromic device and the LED lighting picture in the circuit configured in accordance with FIG.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with another member in between. . In addition, when a part is said to "include" a certain component, this means that it may further include other components, without excluding the other components unless otherwise stated.

1 is a schematic cross-sectional structure of an electrochromic device according to an embodiment of the present invention. Referring to FIG. 1, an electrochromic device according to an aspect of the present invention includes an electrochromic device in which a first electrode 110, an electrochromic layer 120, an electrolyte layer 130, and a second electrode 150 are stacked. In the electrochromic layer is made of an organic material, the thickness of the electrochromic layer may be 5nm ~ 20㎛. In addition, the electrochromic device may further include an electroactive layer 140 between the electrolyte layer and the second electrode. If necessary, a spacer for preventing leakage of the electrolyte layer and maintaining the thickness of the electrolyte layer ( 160 may be further included.

In the electrochromic device having the structure as shown in FIG. 1, when redox occurs in the electrochromic layer, reduction oxidation occurs in the electroactive layer at the same time. In this case, the voltage can be maintained by each oxidized or reduced electrode, and the oxidation is performed. The color change of the electrochromic layer due to reduction also appears at the same time. When the energy storage device is used, the color change can be observed according to the stored energy amount, so that the user can easily use the energy storage device.

The first and second electrodes 110 and 150 may be transparent conductive oxide (TCO). For example, the first and second electrodes may be formed of indium tin oxide (ITO), fluorine doped tin oxide (FTO), or PEDOT: PSS (Poly (3,4-ethylenedioxythiophene): Polystyrenesulfonate), zinc oxide (ZnO), tin oxide (SnO ₂ ), gallium doped zinc oxide (ZnO: Al), boron doped zinc oxide (ZnO: B), or aluminum doped zinc oxide (AZO: Aluminum Zinc Oxide) may be formed of a coated PET electrode or glass.

The electrochromic layer and the electroactive layers 120 and 140 may be provided to the first electrode 110 and the second electrode 150, respectively. The electrochromic layer may change in color as a current flows due to power supply. Accordingly, the transmittance of light can be adjusted.

The electrochromic layer is made of an organic material, the thickness of the electrochromic layer may be 5nm ~ 20㎛. In addition, the electroactive layer may be made of an inorganic material, an organic material, or a combination thereof, preferably, an inorganic material.

The organic material may be a conductive polymer, and the conductive polymer may be polythiophene, polyaniline, polypyrrole, polyanthracene, polyanthracene, polyfluorene, polycarbazole, It may be one selected from the group consisting of polyphenylenevinylene, polyacetylene, polyarylene, derivatives thereof, and combinations of two or more thereof. Specifically, in the electrochromic device having the structure as described above, the polythiophene-based organic material may exhibit electrochromic properties between -0.2V and 1.0V in potential difference from a reference electrode (Reference Electrode, Ag / AgCl). In addition, polyaniline may exhibit electrochromic properties at about 0V to about 0.8V. In addition, when the polythiophene derivative and the polyaniline are applied to the electrochromic layer and the electroactive layer, respectively, when the devices are operated in the range in which they all exhibit electrochromic color, the color difference can be maximized and the device can be stably operated. .

The inorganic material, specifically, the inorganic electrochromic material may be one selected from the group consisting of metals, metal oxides, alloys thereof, polyoxometalates, and combinations of two or more thereof. The inorganic material is tungsten oxide, nickel oxide, vanadium oxide, titanium dioxide, molybdenum oxide, silver (Ag), platinum (Pt), indium oxide, cobalt oxide, niobium oxide, rhodium oxide, iridium oxide, aluminum oxide, lithium oxide, H ₃ PW ₁₂ O ₄₀ , K _0.33 WO _3.16 , H ₉ P ₂ Mo ₁₅ V ₃ , PMo ₉ V ₃ , alloys thereof, and combinations of two or more thereof.

The electrochromic layer may have a thickness of 5 nm to 20 μm, preferably 20 to 200 nm. When the thickness of the electrochromic layer is less than 5 nm, the color density of the energy density and the voltage range of 1 to 1 V may be lowered, and when the thickness of the electrochromic layer is greater than 20 μm, it is inappropriate for integration of devices. In addition, when the electroactive layer is made of an inorganic material, the thickness of the electroactive layer may be 500 to 5,000 nm, preferably 500 to 3,000 nm. When the thickness of the electroactive layer is less than 500 nm, the energy density may be lowered. When the thickness of the electroactive layer is greater than 5,000 nm, the color difference of the voltage range of 1 to 1 V may be lowered.

The electrolyte layer 130 may be located between the electrochromic layer and the electroactive layers 120 and 140. The electrolyte layer 130 may supply an oxidation / reduction material that reacts with the electrochromic material. The electrolyte layer may be a liquid electrolyte in which an electrolyte salt is dissolved, a gel phase electrolyte, a solid electrolyte, a polymer electrolyte, or a liquid electrolyte in which an electrolyte salt is melted. Preferably, the electrolyte layer may be a liquid electrolyte in which an electrolyte salt is dissolved in a solvent.

The electrolyte salt is a salt composed of a cation and an anion, the cation is selected from the group consisting of tetraammonium, magnesium, lithium, sodium, potassium, calcium, azole compound represented by the formula (1) or formula (2) and combinations of two or more thereof and wherein the anion is _{^{BF 4 -, PF 6 -,}} N (CN) 2 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) _{^{6 P -, (CF 3 CF}} 2 SO 2) 2 N -, (CF 3 SO 2) 2 N -, CF 3 SO 3 -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) _{^{2 CH -, (CF 3 SO}} 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 -, CH 3 CO 2 -, thiocyanate, formate, acetate, nitrate, perchlorate , Sulfate, hydroxide, alkoxide, halide, carbonate, oxalate, and combinations of two or more thereof.

<Formula 1>

<Formula 2>

In the above formula, R ₁ ~ R ₁₀ are each independently a hydrogen atom; halogen; An alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, an aryl group, a cycloalkyl group or a benzyl group which may be substituted with one or more NO ₂ or one or more OH; An alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, an allyl group, a cycloalkyl group or a benzyl group which may be substituted with one or more NH ₂ ; It is one selected from the group consisting of an alkyl group having 3 to 10 carbon atoms, alkenyl group, aryl group, allyl group, cycloalkyl group or benzyl group which may be substituted with one or more halogen.

When the electrolyte layer is made of a liquid electrolyte in which an electrolyte salt is dissolved in a solvent, the solvent is a non-aqueous solvent, for example, dichloromethane, chloroform, acetonitrile, ethylene carbonate (EC), propylene carbonate (PC), It may be one selected from the group consisting of tetrahydrofuran (THF), butylene carbonate and a combination of two or more thereof.

In addition, the liquid electrolyte may contain the electrolyte salt in the solvent at a concentration of 0.0001 ~ 10M, preferably, 0.1 ~ 5M, imparting bistable stability (including gel phase polymer and liquid crystal) You may. For example, the liquid electrolyte is one selected from the group consisting of polymethylmethacrylate (PMMA), polyethyleneoxide (PEO), polyvinylidenefluoride (PVDF), polyvinyllidenefluoride-co-hexafluoropropyle-ne (PVDF-HFP), and a combination of two or more thereof. It may be further included, by adjusting the content of these in the liquid electrolyte to 1 to 10% by weight can obtain a higher Colombic Efficiency (Colombic Efficiency) and energy density.

In one embodiment, the electrochromic device may satisfy the following Equation 1.

<Equation 1>

A> 0.5 * B

In the above formula, A is the energy storage density of the electrochromic device after 10,000 charge and discharge, B is the energy storage density of the first electrochromic device.

Figure 6 is a schematic diagram of a system using an electrochromic device according to an embodiment of the present invention. Referring to FIG. 6, the electrochromic device may be used together with an energy generation unit and a sensor unit to be programmed to enable energy storage and discharge autonomously by light, heat, electricity, and the like.

Hereinafter, embodiments of the present invention will be described in detail.

Example 1

PR-Br (Solution A in which 0.05 g of poly (3,3-bis (bromomethyl) -3,4-dihydro-2H-thieno [3,4-b] [1,4] dioxepine)) was dissolved in 100 μl of THF 0.25 g of FeCl ₃ · 6H ₂ O and 0.2 g of poly (ethylene glycol) -block-poly (propylene glycol) -block-poly (ethylene glycol) were dissolved in 0.7 g of 1-butanol, and ITO (Indium Tin Oxide, the first electrode) was applied to the solution of well mixed solution A and B, then spin-coated at 1,500rpm for 30 seconds, and placed on a hot plate at 60 ℃ for 2 hours to polymerize. The polymer applied to ITO was washed with ethanol and dried to form a 170 nm thick electrochromic layer composed of a conductive polymer.

NiOx nanoparticle paste (Solaronix N / SP) was diluted to 20% by weight in ethanol. Fluorine-doped Tin Oxide (FTO) was washed with water, acetone, and ethanol and dried, and two fine holes were drilled. The FTO was spin-coated at 1,500 rpm for 30 seconds and calcined at 500 ° C. for 1 hour to form an electroactive layer having a thickness of 1 μm consisting of nickel oxide having electrochromic properties.

Surlyn (thickness: 100 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was placed on the electroactive layer to have an area of about 3 cm ² , the first electrode coated with the electrochromic layer was covered with a sandwich, and 100 ° C. The electrochromic layer and the electroactive layer were bonded by pressing with a force of 100 N / cm ² using a hot-press of. 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide solution was filled through two holes drilled in the second electrode, and two holes were blocked using silicon to fabricate an electrochromic device.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Example 2

An electrochromic layer was formed on the first electrode as in Example 1.

100mV / s using cyclic voltammetry from -0.2V to 1.2V with ITO working electrode, Ag / AgCl as reference electrode and Pt electrode as counter electrode in aqueous solution of 0.05M, H ₂ SO ₄ 1M After repeated 12 times, it was washed with water and coated with polyaniline (polyaniline) having an electrochromic property within 5% on ITO (second electrode) with an electroactive layer.

A polyimide tape (thickness: 60 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was attached on the electrochromic layer and the electroactive layer to have an area of about 3 cm ² , respectively. When sandwiched in the form of a sandwich, a Pt sheet was additionally inserted so as not to touch the electrochromic layer and the electroactive layer, the second electrode coated with the electroactive layer was covered with a sandwich form, and the electrochromic device was closed by an adhesive. Produced.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. At this time, the potential was checked using a reference electrode (Pt sheet) between the two electrodes, and adjusted to match the dislocation potential range of the electrochromic layer. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Example 3

An electrochromic layer was formed on the first electrode as in Example 1.

100mV / s using cyclic voltammetry from -0.2V to 1.2V with ITO working electrode, Ag / AgCl as reference electrode and Pt electrode as counter electrode in aqueous solution of 0.05M, H ₂ SO ₄ 1M After repeated 12 times, it was washed with water and coated with polyaniline (polyaniline) having an electrochromic property within 5% on ITO (second electrode) with an electroactive layer.

Surlyn (thickness: 100 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was placed on the electrochromic layer so as to have an area of about 3 cm ² , the second electrode coated with the electroactive layer was covered with a sandwich, and 100 ° C. The electrochromic layer and the electroactive layer were bonded by pressing with a force of 100 N / cm ² using a hot-press of. The acetonitrile solution containing 0.1 M perchloric acid (HClO ₄ ) was filled in a solution containing 5% by weight of polymethylmethacrylate through two holes drilled in the second electrode. By using two holes to block the electrochromic device was manufactured.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Example 4

An electrochromic layer was formed on the first electrode as in Example 1.

The TiO ₂ nanoparticle paste (solaronix T / SP) was diluted to 20% by weight in ethanol, spin coated on FTO glass for 1,500 rpm for 30 seconds, and heated at 500 ° C. for 1 hour to form a TiO ₂ film. Ag / AgCl was used as a reference electrode and stainless steel as a counter electrode in the TiO ₂ film, and circulated in an aqueous solution dissolved at a concentration of H ₃ PW ₁₂ O ₄₀ 10 mg / mL at a rate of 100 mV / s from 0.2 V to -1.0 V. After 25 repetitions using the voltammetric method, the mixture was washed with water and dried to form a transparent electroactive layer composed of H ₃ PW ₁₂ O ₄₀ -TiO ₂ .

Surlyn (thickness: 100 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was placed on the electroactive layer to have an area of about 3 cm ² , the first electrode coated with the electrochromic layer was covered with a sandwich, and 100 ° C. The electrochromic layer and the electroactive layer were bonded by pressing with a force of 100 N / cm ² using a hot-press of. 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide solution was filled through two holes drilled in the electroactive layer, and two holes were blocked using silicon to fabricate an electrochromic device.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Example 5

Th-OR (poly (3,4-di (2-ethylhexyloxy) thiophene-co-3,4-di (methoxy) thiophene)) was prepared in a solution of toluene: chloroform = 1: 1 at a ratio of 5% by weight. , It was spray-coated on ITO glass to prepare a red film having a thickness of 120nm.

100mV / s using cyclic voltammetry from -0.2V to 1.2V with ITO working electrode, Ag / AgCl as reference electrode and Pt electrode as counter electrode in aqueous solution of 0.05M, H ₂ SO ₄ 1M After repeated 12 times, it was washed with water and coated with polyaniline (polyaniline) on the ITO (second electrode) with an electroactive layer.

Surlyn (thickness: 100 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was placed on the electrochromic layer so as to have an area of about 3 cm ² , the second electrode coated with the electroactive layer was covered with a sandwich, and 100 ° C. The electrochromic layer and the electroactive layer were bonded by pressing with a force of 100 N / cm ² using a hot-press of. The acetonitrile solution containing 0.1 M perchloric acid (HClO ₄ ) was filled in a solution containing 5% by weight of polymethylmethacrylate through two holes drilled in the second electrode. By using two holes to block the electrochromic device was manufactured.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Comparative Example 1

An electrochromic layer was formed on the first electrode as in Example 1.

Fluorine-doped Tin Oxide (FTO) was washed with water, acetone, and ethanol and dried, and two fine holes were drilled. An electroactive layer was not used.

Surlyn (thickness: 100 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was placed on the electroactive layer to have an area of about 3 cm ² , the first electrode coated with the electrochromic layer was covered with a sandwich, and 100 ° C. The electrochromic layer and the second electrode were joined by pressing with a force of 100 N / cm ² using a hot press of. 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide solution was filled through two holes drilled in the second electrode, and two holes were blocked using silicon to fabricate an electrochromic device.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Comparative Example 2

An electrochromic layer was formed on the first electrode as in Example 1.

100mV / s using cyclic voltammetry from -0.2V to 1.2V with ITO working electrode, Ag / AgCl as reference electrode and Pt electrode as counter electrode in aqueous solution of 0.05M, H ₂ SO ₄ 1M After repeated eight times, washed with water and coated with polyaniline (polyaniline) having an electrochromic property of less than 1% on ITO (second electrode) with an electroactive layer.

A polyimide tape (thickness: 60 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was attached on the electrochromic layer and the electroactive layer to have an area of about 3 cm ² , respectively. When sandwiched in the form of a sandwich, a Pt sheet was additionally inserted so as not to touch the electrochromic layer and the electroactive layer, the second electrode coated with the electroactive layer was covered with a sandwich form, and the electrochromic device was closed by an adhesive. Produced.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. At this time, the potential was confirmed using a reference electrode (Pt sheet) between the two electrodes, and the voltage was set to exceed the dislocation potential range of the electrochromic layer. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Comparative Example 3

An electrochromic layer was formed on the first electrode as in Example 1.

100mV / s using cyclic voltammetry from -0.2V to 1.2V with ITO working electrode, Ag / AgCl as reference electrode and Pt electrode as counter electrode in aqueous solution of 0.05M, H ₂ SO ₄ 1M After repeated 12 times, it was washed with water and coated with polyaniline (polyaniline) on the ITO (second electrode) with an electroactive layer.

Surlyn (thickness: 100 μm) in the form of a hollow rectangle (1.5 cm * 2 cm) was placed on the electrochromic layer so as to have an area of about 3 cm ² , the second electrode coated with the electroactive layer was covered with a sandwich, and 100 ° C. The electrochromic layer and the electroactive layer were bonded by pressing with a force of 100 N / cm ² using a hot-press of. An acetonitrile solution containing 0.1 M perchloric acid (HClO ₄ ) was filled through two holes drilled in the second electrode, and two holes were blocked using silicon to fabricate an electrochromic device.

Ivium I-V was used to measure the amount of energy stored in the device using the cyclic voltamogram of the electrochromic device, and the transmittance was monitored in real time using UV. Chronoamperometry was used to input a constant current into the device, measure the output voltage, and simultaneously measure the transmittance.

Experimental Example 1

The electrochromic layer (material, thickness) and electroactive layer (material, thickness) of the electrochromic devices manufactured according to Examples and Comparative Examples, the energy density and color difference in the voltage range of 1V ~ -1V according to the electrolyte layer Table 1 Shown in

division Electrochromic layer thickness
(nm) Electroactive layer thickness
(nm) Energy density
(Wh / kg) Color difference
(%) Example 1 170 1,000 2.53 71 Comparative Example 1 170 - 10.4 5 Example 2 170 25 10.8 51 Comparative Example 2 170 11 2.55 22 Example 3 170 25 10.8 51 Comparative Example 3 170 25 5.11 50 Example 4 170 3,400 11.5 40

Experimental Example 2

FIG. 2 is a cyclic voltammogram (a) and a charge / discharge graph (b) of an electrochromic device manufactured according to Example 1 and Comparative Example 1 of the present invention, and FIG. 5 is manufactured according to Example 2 of the present invention. The photo is taken when the electrochromic device is charged (1V, -1V) and discharged (0V). 2 and 5, in the case of the polythiophene-based organic electrochromic material, a potential difference from a reference electrode (Reference Electrode, Ag / AgCl) shows an electrochromic property between −0.2V and 1.0V. However, when it is manufactured as an electrochromic device (comparative example 1) consisting of the first electrode / electrochromic layer / electrolyte layer / second electrode /, the maximum electrochromic color is obtained when the voltage reaches about 2.8V. The maximum electrochromic state is applied when 2.8 V is applied. In this case, the amount of energy when the stored energy is discharged is about 2.53 Wh / kg. The first electrode / electrochromic layer / electrolyte layer / electroactive layer / second electrode In the electrochromic device (Example 1) composed of NiOx, the electroactive layer is composed of about 10.4Wh / kg has an increase of about four times the value.

On the other hand, when the electrochromic device is manufactured, a platinum sheet (Pt sheet) may be used as an internal reference electrode in the spacer so as not to contact the first and second electrodes, and thus the potential of the electrochromic device may be checked. At this time, in Comparative Example 1, a potential of about 1.0 V was applied to the electrochromic layer when 2.8 V was applied, and a potential of about 0 V was applied to the electrochromic layer when -2.8 V was applied to the electrochromic device. . On the other hand, in Example 1, a potential of about 1.0V is applied to the electrochromic layer when 1.5V is applied, and a potential of about 0V is applied when -1.0V is applied, thereby producing the maximum color difference in this voltage range. In the same way, the potential of the electroactive layer can be determined, and the range that can maximize the difference in the permeability of the electroactive layer and the range where the difference in the permeability of the electrochromic layer can be maximized can be made. have.

3 is a potential analysis graph (a, b) of the electrochromic device manufactured according to Example 2 and Comparative Example 2 of the present invention, the charge and discharge graph (c) of the device and the stability graph (d) of the change in transmittance. Referring to FIG. 3, in the case of polyaniline, polyaniline exhibits electrochromic properties at about 0V to about 0.8V. In Example 2, polythiophene, an electrochromic layer, was identified by using a Pt sheet as an internal reference electrode. If both the polyaniline and the electroactive layer is operated in a range that exhibits electrochromic color, the color difference can be maximized, and the device can be operated stably.

4 is a charge / discharge graph (a), a cyclic voltammogram (b) and a transmittance change graph (c) of the electrochromic devices manufactured according to Example 3 and Comparative Example 3 of the present invention. Referring to FIG. 4, the electrochromic device of Example 3, in which polymethyl methacrylate (PMMA) is dissolved in a liquid electrolyte, may obtain higher Colombic Efficiency and energy density.

Experimental Example 3

The electrochromic device fabricated in Example 1 was used as an electrochromic capacitor to produce the circuit diagram of FIG. 7. In Fig. 7, R1 to R8 are resistors, Q1 and Q2 are transistors, and the one consisting of R1, R2 and C1 inside the blue rectangle is an equivalent circuit of the electrochromic capacitor. V1 and V2 are batteries.

20 Ω for R3, R6, 50 kΩ for R4, 1 kΩ for R7, 1.0 V for V1, V2, 2SA1015 for Q1, Q2, GL4526 as an optical sensor, and the device manufactured in Example 1 with an electrochromic capacitor. Used. At this time, the ambient light amount shows blue at 100 lux or more, purple at 40 to 100 lux, and transparent color at 40 lux or less, and when it is used as a smart window, it can autonomously adjust the amount of light entering the interior according to the amount of external light. have. In addition, the energy stored in the electrochromic capacitor may be used as an energy source capable of operating external electric devices.

Experimental Example 4

The electrochromic devices fabricated in Examples 1 and 5 were used as the electrochromic capacitors to produce the circuit diagram of FIG. 8. R1 and R2 are resistors, Q1 to Q4 are transistors, O1 and O2 are OPAMPs, and TC1 and TC2 are temperature sensors.

Here, 1kΩ for R1, 5kΩ for R2, 2SA1015 for Q1 to Q4, LM2904N for O1, O2, and k-type thermocouple for TC1 and TC2, and the external electronic device was red LED and electrochromic capacitor 1 Example 1 The device manufactured in Example 5 was connected to the device manufactured in Example 5 by using an electrochromic capacitor 2.

FIG. 9 is a photograph of an electrochromic capacitor and a photograph of LED lighting in a circuit constructed according to FIG. 8. Referring to FIG. 9, in the manufactured system, the electrochromic capacitor 1 is transparent at 60 ° C. or higher, the electrochromic capacitor 2 is red, at 20 ° C. or higher and 60 ° C. or lower, the electrochromic capacitor 1 is purple, and the electrochromic capacitor 2 is gray. At 20 ℃ or below, electrochromic capacitor 1 is blue, electrochromic capacitor 2 is transparent, and the temperature can be shown to the user as a display according to the temperature, and the energy stored in the electrochromic capacitor shown in blue, transparent, and red is shown in the circuit diagram. By closing the connected switch, it could be used as an energy source for external electronic devices such as LEDs.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the invention is indicated by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the invention.

Claims (10)

In an electrochromic device in which a first electrode, an electrochromic layer, an electrolyte layer, an electroactive layer, and a second electrode are sequentially stacked,
The electrochromic layer is made of a polythiophene derivative,
The thickness of the electrochromic layer is 5nm ~ 20㎛,
The color difference of the electrochromic device is more than 40% in the voltage range of + 1V ~ -1V,
The electrochromic device has an energy density of 2.53 Wh / kg or more. delete delete The method of claim 1,
The electroactive layer is an electrochromic device consisting of an inorganic material, an organic material, or a combination thereof. The method of claim 4, wherein
Electrochromic device of the thickness of the electroactive layer is 500 ~ 5,000nm. The method of claim 4, wherein
The inorganic material is an electrochromic device selected from the group consisting of metals, metal oxides, alloys thereof, polyoxometalate, and combinations of two or more thereof. The method of claim 1,
The electrolyte layer is an electrochromic device which is a liquid electrolyte in which an electrolyte salt is dissolved, a gel phase electrolyte, a solid electrolyte, a polymer electrolyte, or a liquid electrolyte in which an electrolyte salt is melted. The method of claim 7, wherein
The electrolyte salt is a salt consisting of a cation and an anion,
The cation is one selected from the group consisting of tetraammonium, magnesium, lithium, sodium, potassium, calcium, azole compound represented by the formula (1) or formula (2) and a combination of two or more thereof,
Wherein the anion is _{^{BF 4 -, PF 6 -,}} N (CN) 2 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P _{^{-, (CF 3 CF 2 SO}} 2) 2 N -, (CF 3 SO 2) 2 N -, CF 3 SO 3 -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH _{^{-, (CF 3 SO 2)}} 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 -, CH 3 CO 2 -, thiocyanate, formate, acetate, nitrate, perchlorate, sulfate An electrochromic device selected from the group consisting of hydroxides, alkoxides, halides, carbonates, oxalates, and combinations of two or more thereof:
<Formula 1>

<Formula 2>

In the above formula,
R ₁ to R ₁₀ are each independently a hydrogen atom; halogen; An alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, an aryl group, a cycloalkyl group or a benzyl group which may be substituted with one or more NO ₂ or one or more OH; C1-C10 alkyl group, alkenyl group, aryl group, allyl group, cycloalkyl group, or benzyl group which may be substituted with one or more NH ₂ ; It is one selected from the group consisting of an alkyl group having 3 to 10 carbon atoms, alkenyl group, aryl group, allyl group, cycloalkyl group or benzyl group which may be substituted with one or more halogen. The method of claim 7, wherein
The liquid electrolyte further comprises one selected from the group consisting of polymethylmethacrylate (PMMA), polyethyleneoxide (PEO), polyvinylidenefluoride (PVDF), polyvinyllidenefluoride-co-hexafluoropropyle-ne (PVDF-HFP), and a combination of two or more thereof. Discoloration element. The method according to any one of claims 1 to 4, wherein
An electrochromic device that satisfies Equation 1 below.
<Equation 1>
A> 0.5 * B
In the above equation,
A is the energy storage density of the electrochromic device after 10,000 charge and discharge cycles,
B is the energy storage density of the first electrochromic device.

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