RU2758201C2 - Counter electrode of an electrochromic apparatus and the method for manufacture thereof - Google Patents

Abstract

FIELD: electric elements.

SUBSTANCE: invention relates to applied electrochemistry, namely to a composition and a method for manufacturing a counter electrode for electrochromic apparatuses with an electrically controlled value of light transmittance. The counter electrode for electrochromic apparatuses consists of a counter substrate, a transparent electrically conductive material and an active counter electrode layer made of sol containing lithium, nickel and titanium, wherein, in order to improve the solubility of the compounds of said metals in alcoholic solutions, the sol includes 1 to 10% of complexing agents selected from: monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, triethyleneamine, diethylenediamine, cysteamine (thioethanolamine), amino mono-, di- and triacetic, aminopropionic, aminobutyric, ethylenediaminetetraacetic acids and derivatives thereof, oxalic, tartaric, citric acids, acetylacetone, acetoacetic ether and derivatives thereof, cyclohexanedione and derivatives thereof, polyethylenimine, oligo- and polyacrylates.

EFFECT: improved technology for manufacturing a counter electrode.

9 cl, 1 dwg

Description

The technical field to which the invention relates

The invention relates to applied electrochemistry, namely to a composition and a method for manufacturing a counter electrode for electrochromic devices with an electrically controlled light transmission. According to the claimed invention, a sol for applying a protoelectrode is characterized by ease of preparation, high stability, and the ability to scale to large loads. The process of obtaining a counter electrode is characterized by a high rate of heat treatment. The counter electrode obtained according to the present invention has high transparency in the discolored state and has a neutral gray color in the colored state, due to which the electrochromic efficiency of electrochromic devices based on the described counter electrode is on average twice as high as similar devices with a passive counter electrode due to the simultaneous coloring of both electrodes; there are no opaque elements (dots, strokes, etc.).

State of the art

Electrochromic devices are designed to regulate the light and heat fluxes passing through them. Structurally, electrochromic devices are a multilayer material, the upper and lower layers of which have a solid or flexible substrate or a counter-substrate made of glass or polymer material. A transparent conductive material based on a transition metal oxide (TCO, transparent conductive oxide), 6 in particular: tin-doped indium oxide or fluorine-doped tin oxide, is deposited on the inner surface of the substrate or counter-substrate. An electrochromic layer of a metal oxide is applied to the surface of a transparent electrically conductive material, in particular: oxide of tungsten, niobium, vanadium, iridium or their mixtures, and / or an electroactive polymer, in particular: polyaniline or polypyrrole, or polythiophene, or their derivatives.

The structure "substrate / transparent electrically conductive material / electrochromic layer" is called a working electrode, and the structure "counter substrate / transparent electrically conductive material / active layer" is called a counter electrode, while an active layer of a metal oxide (for example, vanadium oxide, titanium , cerium, niobium, nickel or mixtures thereof), from a complex salt or other substance, may or may not have electrochromic properties.

Staining / discoloration of an electrochromic device occurs by passing a direct electric current in the forward or reverse direction.

To achieve the greatest coloration (toning) of an electrochromic device, it is necessary that the counter electrode has electrochromic properties, and the direction of the current causing coloration / discoloration of the counter electrode should be opposite to the direction of the current causing coloration / discoloration of the working electrode. In other words, if a cathodic electrochromic process occurs on the working electrode, then an anodic electrochromic process should occur on the counter electrode and vice versa.

The present invention discloses a method of manufacturing a counter electrode with an anode electrochromic material, which can be used in electrochromic devices with a working electrode based on a cathode electrochromic material.

The patents of the Japanese corporation Nippon are known from the prior art, in which the formulas of counter electrodes / 1, 2 / are disclosed and embodiments of electrochromic devices based on them are given. Thus, in the inventions claimed by Nippon Oil Co., the counter electrodes are composed of an electrically conductive substrate and a plurality of capacitive elements attached to the substrate. Each of the capacitive elements consists of small particles bonded with a binder (silicone or epoxy or epoxysilane) / 2 /. The size of particles of various shapes is in the range of 0.1-500 microns. The materials used for the manufacture of the counter electrode are: porous carbon, intercalation materials (disulfides TiS ₂ , MoS ₂ ; dioxides CoO ₂ , NiO ₂ , electrochromic oxides W ₁₈ O ₄₈ , W ₂₀ O ₃₈ ) or electrically conductive polymers (polyaniline, polypyrrole , polythiophene) and mixtures thereof. To improve conductivity, a conductive material is used, such as graphite, acetylene black, fine metal particles or conductive polymers.

The patents "Counter electrode for smart glass and smart glass" / 1, 2 / disclose a counter electrode for smart glass ("smart window" or smart window), consisting of a transparent substrate and an electrically conductive material having a specific surface area of at least 10 m ² /G. As an electrically conductive material, porous carbon and electrically conductive polymers (polythiophene, polypyrrole, polyaniline, etc.) or their mixtures can be used. _{Porous metal oxides NiO, Cr 2} O ₃ , CuO, Al ₂ O ₃ , SiO ₂ can be added to the electrically conductive material. The electrically conductive material is applied in the form of stripes, straight or curved lines, grids of straight lines, and in the form of any possible planar geometric shapes. The preferred configuration of the capacitive particles on the surface of the conductive substrate: dots or stripes.

If the particles are combined in lines, their width depends on the used electrochromic material and electrically conductive material and is usually from 5 μm to 1 cm. The distance between the lines is from 1 mm to 10 cm / 1 /.

If the particles are combined into points, then the size of the circumscribing circle should be from 0.05 to 10.0 mm. The thickness of the dots is usually at least 0.050 mm. The spacing between the points depends on the capacity, usually from 0.2 mm to 10 cm. The percentage of surface coverage with capacitive elements is in the range from 3% to 70% / 2 /. Particle sizes are not uniform.

The disadvantage of this technical solution is the large proportion of the glass surface area covered with an opaque material. This disadvantage of an electrochromic device leads to a decrease in the transmission of visible light and a deterioration in the appearance of the device, since the points or strips of the counter electrode, due to their size, are distinguishable by the naked eye from a distance of up to 10 m.

From the prior art / 3 / a counter electrode for an electrochromic device based on Prussian blue is known: a mixture of hexacyanoferrates from KFe [Fe (CN) ₆ ] to Fe ₄ [Fe (CN) ₆ ] ₃ , preferably in the form of iron (II) ferricyanide Fe ₃ [Fe (CN) ₆ ] ₂ . The disadvantages of this counter electrode are: self-discoloration at temperatures above 50 ° C; degradation by UV radiation; low electrochemical stability in the discolored state; insufficient heat and moisture resistance. In addition, the tungsten oxide and Prussian blue system does not maintain the electrochemical balance required for complete discoloration of the device, so recharging of the counter electrode is required before starting work.

A number of technical solutions are known in which the counter electrode is made on the basis of metal oxides of transition groups having a variable oxidation state: Ni, Cr, Mn, V, Fe, etc. Thus, the patent / 4 / describes the counter electrode from the gamma phase Li _x V ₂ O ₅ , x = 0.7-2.0, for fully solid-state electrochromic devices. One of the problems in the preparation of this counter electrode is the growth of microcrystals during the conversion of amorphous Li _x V ₂ O ₅ to the gamma phase, leading to cracking and haze due to light scattering.

For the material of the counter electrode, Ni oxide has certain advantages due to its electrochemical stability, neutral gray shade in the colored state, and a large number of switching cycles. Improving the parameters of nickel oxide is achieved by introducing various doping elements.

A number of technical solutions are known in which the counter electrode is manufactured by magnetron sputtering on a substrate, for example, patent / 5 /, in which the compositions Li _a EC ₁ M1 _b M2 _c O _x are patented, where a: 0.5 ... 3; b + c: 0.1 ... 1; s / (b + s): 0.1 ... 0.9; x: 0.1 ... 50; EC is selected from the group of mixtures of Ni (II) and Ni (III); Co (II) and Co (III); Ir (IV) and Ir (V); Mn (II), Mn (III), and Mn (IV); M1 is selected from the group Zr (IV); Hf (IV): Ta (V); Nb (V); and W (VI); M2 is selected from group V (V); Ta (V); Mo (VI); Nb (V): Mn (IV); La (III); and Ce (IV). For example Li _1.82 NiW _0.45 O _x ; Li _1.97 NiZr _0.23 O _x , etc. Materials are applied by joint magnetron sputtering from alloy targets in an Ar / O ₂ atmosphere. Thickness 80-200 nm.

In the patent / 6 / it is proposed to apply Ni oxide by reactive cathode sputtering in the presence of hydrogen plasma.

The patent / 7 / describes anodically painted Ni-based materials for the manufacture of a counter electrode (without limiting the list): NiWO, NiWTaO, NiWSnO, NiWNbO, NiWZrO, NiWAlO, NiWSiO, NiTaO, NiSnO, NiNbO, NiZrO, NiOAlO, a, NiSi mixtures. Application methods may include: physical vapor deposition, chemical vapor deposition, plasma chemical vapor deposition, atomic layer deposition. Co-deposition with Li is possible.

In the patent / 8 / an anodically-painted layer is claimed - nickel-tungsten-olozo oxide in various ratios, NiWSnO, characterized by a special transparency in the discolored state. May also include Li or other charge carrier. Application methods may include: physical vapor deposition, chemical vapor deposition, plasma chemical vapor deposition, atomic layer deposition.

In the patent / 9 / an anodically-painted layer is claimed - nickel-tungsten-niobium oxide in various ratios, NiWNbO, characterized by a special transparency in the discolored state. May also include Li or other charge carrier. Application methods may include: physical vapor deposition, chemical vapor deposition, plasma-assisted chemical vapor deposition, atomic layer deposition.

In the patent / 10 / an anodically-painted layer is declared - nickel-tungsten-tantalum oxide in various ratios, NiWTaO, characterized by a special transparency in the discolored state. May also include Li or other charge carrier. Application methods may include: physical vapor deposition, chemical vapor deposition, plasma chemical vapor deposition, atomic layer deposition.

The disadvantages of methods of vacuum deposition of materials include:

- low rates of deposition of oxide materials;

- heterogeneity of application, both in the thickness of the layers and in their chemical composition;

- limited ability to control the chemical composition and microstructure;

- limited selection of raw materials;

- low yield of usable glasses;

- high operating costs.

An alternative method is the use of sol-gel technology. This is a vacuum-free technology that requires relatively inexpensive equipment. Easily scalable to large areas (several square meters). It is economical for producing both thin and thick oxide films. It is easy to obtain films of mixed composition by mixing solutions. The deposition of a counter electrode layer, in particular of doped nickel oxide, in the form of a thin (300 - 600 nm) film using the sol-gel technology includes a number of stages:

1) preparation of a nickel oxide precursor;

2) the formation of a sol;

3) applying a sol to glass with a transparent electrically conductive coating;

4) drying of the applied layer;

5) heat treatment and formation of an electrochromic nickel oxide film.

The patent / 11 / claims a multilayer electrochromic structure, including an anodic electrochromic layer on a substrate, which includes Li-Ni - an oxide composition with at least one of the metals of group 4: Ti, Zr, Hf. The process of forming a multilayer electrochromic structure includes applying a liquid mixture to a substrate and processing it to obtain an anodic electrochromic layer. Among the elements that stabilize the discolored state are also declared: Y, V, Nb, Ta, Mo, W, B, Al, Ga, In, Si, Ge, Sn, P, Sb and their mixtures. The composition of the liquid for applying the anodic electrochromic layer includes organic or inorganic Li compounds: hydroxide, carbonate, nitrate, sulfate, peroxide, bicarbonate, etc. From organic - various, for example, amides, alkoxides, carboxylates, lithium diketonates. And also polyoxometallates such as Keggin's salts: heteropolytungstates and heteropolymolybdates. Possible Ni compounds are also listed. As solvents, water, alcohols, carboxylic acids, alkylamines, alkanes, alkenes, their mixtures, as well as dimethylformamide, dimethyl sulfoxide, methylpyrrolidone, acetonitrile, acetone, ethyl acetate, trioctylphosphine, trioctylphosphine oxide, tetrahydrofuran, dioxane can be used. Salts of Li, Ni and Group 4 metal are dissolved or dispersed in a solvent under an inert atmosphere. The solvent may contain additives: to improve solubility, complexing agents (organic acids, carbonates, amines, polyesters), moisturizers (propylene glycol, etc.) to improve the quality of the applied layers. If a water-based solvent is taken, then water-soluble precursors of Li and Ni are used: nitrates, hydroxides, carbonates, acetates.

Preparation of the anode layer includes the following stages: application of liquid to the substrate, evaporation of the solvent, heat treatment.

Application methods may include: meniscus coating, roll coating, deep coating, spin coating, spray coating, screen coating, printer coating, knife roll coating, metering rod coating, curtain coating coating). As well as spraying drops by aerosol or printer method. After application, the substrate is placed in a stream of air, either in a vacuum, or heated to remove the solvent. Then it is annealed at a temperature of 200 to 700 ° C.

It is impossible to deduce a specific implementation of any composition (precursor) and method of applying an electrochromic film from the text of this patent.

Methods for producing a precursor of lithiated nickel oxide based on various chemical processes are also known from the prior art. The authors / 12 / describe the preparation of a precursor by mixing aqueous solutions of lithium nitrate and hexahydrate of nickel nitrate, followed by the addition of citric acid as a chelating agent. Then the resulting sol is dried and annealed to form a structure at 800 ° C. To obtain a coating, the synthesized oxide is mixed with acetylene black, and polytetrafluoroethylene is added as a binder.

The disadvantages of this method are the high annealing temperature and the lack of transparency in the final coating. In addition, this method is not suitable for the production of coatings on glass by dip- and spray-coating methods.

The authors / 13 / describe the preparation of nickel oxide films on the glass surface by keeping the substrate for 60 minutes in an aqueous solution of nickel nitrate and polyvinyl alcohol. After the coating is heated in a microwave oven at 200 ° C for 10 minutes (65 W, 7 Hz).

The disadvantages of this method are low stability of pure nickel oxide during cycling, brown color of the film, as well as limited scaling for large glass due to the lack of microwave ovens of the required size on the market (substrate size up to 1500 * 3200 mm).

The source / 14 / describes the preparation of coatings based on TiO ₂ -NiO by dissolving lithium acetate tetrahydrate in alcohol, followed by the addition of titanium isopropoxide. However, the process of sol synthesis and coating is carried out in an inert atmosphere of a glove box, which is extremely problematic to scale up to large glass sizes. In addition, the absence of lithium ions in the resulting coating suggests the need to precharge the coating to use it as a counter electrode in the EC device.

Describes / 15 / obtaining films TiO ₂ -NiO on the principle of the core-shell. This material is characterized by a high exchange capacity and rich color in the oxidized state. However, the disadvantages of this method are the complexity of the synthesis of the core-shell structure, insufficiently high reversibility and the need to precharge the coating for use as a counter electrode for devices based on tungsten oxide.

The closest solution (prototype) is a method for preparing a precursor by dissolving 3.48 g of nickel acetate tetrahydrate and 0.77 g of lithium acetate in 50 ml of ethanol, followed by the addition of 1 ml of titanium isopropoxide, the solution is stirred for 30 minutes, then filtered / 16/. A freshly prepared sol is applied by spin-coating onto a 3.5 * 3.5 cm substrate, annealed for 30 minutes at 300 ° C, the rate of temperature rise is 2 ° C / min. However, in this technique, the authors, obviously, do not indicate more detailed conditions for the synthesis of the sol, since these substances do not dissolve in ethanol under the described conditions. In addition, the addition of titanium isopropoxide is accompanied by hydrolysis with the formation of a difficult-to-separate precipitate, as a result of which the freshly prepared sol can be used only immediately after preparation for a short period of time, which is a significant disadvantage. To achieve a thickness of 100 nm, the film is applied by spin-coating. Drying is carried out in air at 110 ° C, annealing in air at 300 ° C for 30 min / 16 /.

The disadvantage of this method is the need for multiple applications to obtain the required thickness, which increases the number of film defects and labor costs.

The aim of the claimed invention was the development of a counter electrode for electrochromic devices, as well as a method for its manufacture, devoid of these disadvantages.

The objective of the invention was to improve the techniques taken as a prototype in order to improve manufacturability and ease of production.

The task in terms of preparing the precursor is solved by adding the following additional components to the solution.

1. Improving the solubility of Li, Ni, Ti compounds is achieved by adding complexing agents in an amount of 1-10 wt%, preferably in an amount of 3-7 wt%, selected from among: monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, triethyleneamine, diethylene diamine, cysteamine (thioethanolamine), amino mono-, di- and triacetic, aminopropionic, aminobutyric, ethylenediaminetetraacetic, oxalic, tartaric, citric acids, acetylacetone, acetoacetic ether and its derivatives, cyclohexanedione and its derivatives, polyethyleneimine, polyacrylates without limitation. This additive allows you to obtain a solution of components in a wide range of ratios and concentrations.

2. Stabilization and prevention of sol gelation due to hydrolysis of titanium isopropoxide is achieved by adding cosolvents in an amount of 5-20% by weight, preferably in an amount of 8-15% by weight, selected from: glyme (ethylene glycol dimethyl ether), diglyme (diethylene glycol dimethyl ether) ), butyl cellosolve, ethyl cellosolve, without limiting the list. This additive makes it possible to work with the precursor in air, without using an inert atmosphere. In addition, the use of a complexing agent and a stabilizer contributes to the possibility of long-term storage of the obtained sol, which eliminates the disadvantage of the prototype for the use of freshly prepared sol for applying.

3. Improving the wettability of substrates and controlling the rate of drying of the solvent from the applied film is achieved by adding cosolvents in an amount of 10-30 wt%, preferably in an amount of 10-20 wt%, selected from: propanol, isopropanol, butanol, butanediol, ethylene glycol, polyethylene glycol of various molecular weights, propylene glycol, polypropylene glycol of various molecular weights, glycerin, propylene carbonate, diethyl carbonate, acetone, methyl ethyl ketone, diethyl ketone without limitation of the list. This additive makes it possible to apply a precursor film of the desired thickness (for example, by ultrasonic spraying), thus obtaining a high quality film, uniform, without cracking, characterized by improved dynamics of staining / discoloration.

Example 1.

Sol preparation

90 ml were mixed in the flask. 98% ethanol and 10 ml. butyl cellosolve. Added 4 g of lithium chloride dihydrate, stirred until complete dissolution. After added 10 g of nickel chloride tetrahydrate and 5 ml. aminoethanol. The mixture was stirred at 80 ° C until complete dissolution, and then cooled to room temperature. Then 15 ml of methyl ethyl ketone, 6 ml was added in small portions with stirring. titanium isopropoxide, stirring continued for 30 minutes. Then the solution was filtered (filter pore size 45 μm) or centrifuged at 10,000 rpm for 10 minutes. The finished sol was stored in a freezer at -20 ° C. The sol was warmed to room temperature before application.

Film application

A film of the prepared sol was applied to K-glass by dip-coating using a KSV DX2S dip-coater, the ascent rate was 70–90 cm / min, and the sample was immersed in the sol once.

Heat treatment

Annealing was carried out at 350 ° C for 30 minutes in a SNOL muffle electric furnace, the temperature was raised for 1 hour. The film thickness was 550 nm; measurements were carried out on a Quanta 3D FEG.

Example 2.

Sol preparation

90 ml were mixed in the flask. 98% ethanol and 8 ml. diglyma. Added 4 g of lithium acetate dihydrate, stirred until complete dissolution. After added 12 g of nickel acetate tetrahydrate and 3 ml. cysteamine. The mixture was stirred at 60 ° C until complete dissolution, and then cooled to room temperature. Then 15 ml of propylene carbonate, 5 ml was added in small portions with stirring. titanium isopropoxide, stirring continued for 30 minutes. Then the solution was filtered (filter pore size 45 μm) or centrifuged at 10,000 rpm for 10 minutes.

The finished sol was stored in a freezer at -20 ° C. The sol was warmed to room temperature before application.

Film application

A film of the prepared sol was applied to K-glass by the method of ultrasonic spraying, the liquid flow rate was 0.05-0.5 g / dm ² , the spraying was carried out once.

Heat treatment

Drying was carried out in air for 60 min. Then annealing was carried out at 350 ° C for 30 minutes in a SNOL muffle electric furnace, the temperature was raised for 1 hour. The film thickness was 500 nm.

Example 3.

Sol preparation

90 ml were mixed in the flask. 98% ethanol and 12 ml. ethyl cellosolve. Added 5 g of lithium nitrate trihydrate, stirred until complete dissolution. After added 14 g of nickel nitrate tetrahydrate and 6 ml. ethylenediamine. The mixture was stirred at 70 ° C until complete dissolution, and then cooled to room temperature. Then 12 ml of diethyl ketone, 6 ml was added in small portions with stirring. titanium isopropoxide, stirring continued for 40 minutes. Then the solution was filtered (filter pore size 45 μm) or centrifuged at 10,000 rpm for 10 minutes. The finished sol was stored in a freezer at -20 ° C. The sol was warmed to room temperature before application.

Film application

A film of the prepared sol was applied to K-glass by the method of ultrasonic spraying, the liquid flow rate was 0.05-0.5 g / dm ² , the spraying was carried out once.

Heat treatment

Drying was carried out in air for 40 min. Then annealing was carried out at 300 ° C for 40 minutes in a SNOL muffle electric furnace, the temperature was raised for 1 hour. The film thickness was 600 nm.

Brief Description of Drawings

The claimed invention is illustrated by a drawing. FIG. 1 shows the external view of the counter electrode, side view. The positions in FIG. 1 are marked:

1 - counter substrate;

2 - transparent electrically conductive material;

3 - active layer of the counter electrode.

Sources of information:

/ 1 / Patent US 5940202, IPC: G02F 1/155. Counterelectrode for smart window and smart window. Published: 17.08.1999. Status: valid.

/ 2 / Patent US 5708523 (A), IPC: G02F 1/155. Counterelectrode for smart window and smart window. Published: 13.01.1998. Status: valid.

/ 3 / Patent RU 2534119 (C2), IPC: C09K9 / 02, G02F1 / 15. Electrochromic device with lithium polymer electrolyte and method for its manufacture. Published: 27.11.2014. Status: valid.

/ 4 / Patent US 5919571, IPC: В32В 17/00. Counterelectrode layer (translation: "Counter-electrode layer"). Published: 6.07.1999. Status: valid.

/ 5 / Patent US 8995041 B2, IPC: G02F 1/55, C23C 14/08, G02F 1/15. Published: 03/31/2015; WO 2014/025876 A2, IPC G02F 1/15. Published: 13.02.2014. Ternary nickel oxide materals for electrochromic devices (translation: "Ternary nickel oxide materials for electrochromic devices"). Status: valid.

/ 6 / Patent US 5164855, IPC: G02F 1/01. Counter electrode for electrochromic systems (translation: "Counter electrode for electrochromic systems"). Published: 17.11.1992. Status: valid.

/ 7 / Patent US 2017/0003564 A1, IPC: G02F 1/155, G02F 1/1343, G02F 1/15. Counterelectrode for electrochromic devices (translation: "Counter electrode for electrochromic devices"). Published: 5.01.2017. Status: valid.

/ 8 / Patent US 10345671 B2, IPC: G02F 1/153, G02B 26/00. Counter electrode for electrochromic devices (translation: "Counter electrode for electrochromic devices"). Published: 9.07.2019. Status: valid.

/ 9 / Patent US 10228601 B2, IPC: G02F 1/15, G02F 1/03. Counter electrode for electrochromic devices (translation: "Counter electrode for electrochromic devices"). Published: 12.03.2019. Status: valid.

/ 10 / Patent WO 2016/085823 A1, IPC: G02F 1/155. Counter electrode for electrochromic devices (translation: "Counter electrode for electrochromic devices"). Published: 2.06.2016. Status: valid.

/ 11 / Patent WO 2014/113801 A1, IPC: G02F 1/15. Electrochromic lithium nickel group 4 mixed metal oxides (translation: "Electrochromic mixed oxides of lithium, nickel and group 4 metals"). Published: 24.07.2014. Status: valid.

/ 12 / Synthesis by sol-gel method and electrochemical properties of LiNiO ₂ cathode material for lithium secondary battery. Myoung Youp Song, Ryong Lee / Journal of Power Sources 111 (2002) 97-103.

/ 13 / Nickel Oxide Thin Film Synthesis by Sol-Gel Method on Glass Substrates. Khadher AL-Rashedi, Mazahar Farooqui, Gulam Rabbani / International Journal of Universal Print 4 (8), (2018), 508-516.

/ 14 / Electrochromism of NiO-TiO ₂ sol gel layers. A. Al-Kahlout, S. Heusing MA, Aegerter J Sol-Gel Sci Techn 39, (2006), 195-206.

/ 15 / Constructed TiO ₂ / NiO Core / Shell Nanorod Array for Efficient Electrochromic Application. Guofa Cai, Jiangping Tu, Ding Zhou, Lu Li, Jiaheng Zhang, Xiuli Wang and Changdong Gu / J. Phys. Chem. 118 (2014), 6690-6696.

/ 16 / Enhanced electrochromic performances and cycle stability of NiO-based thin films via Li-Ti co-doping prepared by sol-gel method. Junling Zhou, Gui Luo, Youxiu Wei, Jianming Zheng, Chunye Xu / Electrochimica Acta 186 (2015) 182-191.

Claims (9)

1. A counter electrode for electrochromic devices, consisting of a counter substrate, a transparent electrically conductive material and an active layer of a counter electrode made of a sol containing lithium, nickel and titanium, characterized in that to improve the solubility of the compounds of these metals in alcohol solutions, 1-10 % of complexing agents selected from: monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, triethyleneamine, diethylenediamine, cysteamine (thioethanolamine), amino mono-, di- and triacetic, aminopropionic, aminobutyric, ethylenediaminetetraacetic acids, citric acids acetylacetone, acetoacetic ether and its derivatives, cyclohexanedione and its derivatives, polyethyleneimine, oligo- and polyacrylates. 2. The counter electrode for electrochromic devices according to claim 1, characterized in that to stabilize the sol and prevent hydrolysis of titanium isopropoxide, 5-20% of co-solvents selected from the number of glyme (ethylene glycol dimethyl ether), diglyme (diethylene glycol dimethyl ether) are added to the sol composition , butyl cellosolve, ethyl cellosolve. 3. The counter electrode for electrochromic devices according to claim 1, characterized in that to improve the wettability of the substrates and control the rate of drying of the solvent from the applied film, 10-25% of co-solvents selected from the number of propanol, isopropanol, butanol, butanediol, ethylene glycol are added to the sol composition , polyethylene glycol of various molecular weights, propylene glycol, polypropylene glycol of various molecular weights, glycerin, propylene carbonate, diethyl carbonate, acetone, methyl ethyl ketone, diethyl ketone. 4. Sol for the manufacture of a counter electrode for electrochromic devices, containing lithium, nickel and titanium, characterized in that to improve the solubility of the compounds of these metals in alcohol solutions, 1-10% of complexing agents are added to the sol composition, selected from: monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, triethyleneamine, diethylenediamine, cysteamine (thioethanolamine), amino mono-, di- and triacetic, aminopropionic, aminobutyric, ethylenediaminetetraacetic acids and their derivatives, oxalic, tartaric, citric acids, acetylacetone, acetoacetic and its derivatives, its derivatives polyethyleneimine, oligo- and polyacrylates without limitation of the list. 5. Sol for the manufacture of a counter electrode for electrochromic devices according to claim 4, characterized in that to stabilize the sol and prevent hydrolysis of titanium isopropoxide, 5-20% of co-solvents selected from the number of glyme (ethylene glycol dimethyl ether), diglyme (dimethyl diethylene glycol ether), butyl cellosolve, ethyl cellosolve, without limiting the list. 6. Sol for the manufacture of a counter electrode for electrochromic devices according to claim 4, characterized in that to improve the wettability of the substrates and control the rate of drying of the solvent from the applied film, 10-25% of co-solvents selected from among: propanol, isopropanol, butanol, are added to the sol composition. butanediol, ethylene glycol, polyethylene glycol of various molecular weights, propylene glycol, polypropylene glycol of various molecular weights, glycerin, propylene carbonate, diethyl carbonate, acetone, methyl ethyl ketone, diethyl ketone without limitation of the list. 7. A method of obtaining a sol for making a counter electrode for electrochromic devices according to claim 4, comprising completely dissolving a lithium salt in a mixture of 85% ethanol and a co-solvent that prevents hydrolysis and a co-solvent that improves the wettability of the substrate; adding nickel salt and complexing agent, stirring with heating until complete dissolution, followed by cooling to room temperature; adding titanium isopropoxide to the resulting mixture in small portions, with stirring for 30 minutes; filtration or centrifugation of the resulting mixture, while all operations are carried out in air, without using a glove box with an inert atmosphere. 8. A method for producing an active layer of a counter electrode for manufacturing a counter electrode for electrochromic devices according to claim 1, characterized in that the sol is applied by dip-coating with a single immersion or by the method of ultrasonic spraying. 9. A method for producing an active layer of a counter electrode for manufacturing a counter electrode for electrochromic devices according to claim 8, characterized in that the applied film is annealed at a high rate of temperature rise - 6 ° C / min, holding at a maximum temperature - 30 minutes.

Images