KR101911376B1 - Gel polymer electrolyte composition and electrochromic device using the same - Google Patents

Abstract

The present invention relates to a gel polymer electrolyte composition and an electrochromic device using the gel polymer electrolyte composition, and more particularly to a gel polymer electrolyte composition comprising a tetrafunctional (meth) acrylate compound represented by Chemical Formula 1 or Chemical Formula 2, an ionic liquid, a photopolymerization initiator, To an electrochromic device using the gel polymer electrolyte composition and an electrochromic device using the gel polymer electrolyte composition.

Description

TECHNICAL FIELD [0001] The present invention relates to a gel polymer electrolyte composition and an electrochromic device using the gel polymer electrolyte composition.

The present invention relates to a gel polymer electrolyte composition which has improved curability and ionic conductivity to ensure excellent electrochromic properties, and an electrochromic device using the gel polymer electrolyte composition.

Elctrochromic devices are devices that change the light transmission characteristics by using the principle that the electric oxidation-reduction reaction proceeds according to the application of the electric field to change the color of the electrochromic material. This is widely used not only for display devices such as mobile phones, camcorders, notebooks, but also for automobile room mirrors and window smart windows.

1, the electrochromic device generally includes first and second electrodes 10 and 20 formed with transparent electroconductive layers 12 and 22 on a substrate 11 and 21 to which an electric field is applied, The electrochromic material layer 31 and 32 are laminated on the conductive layers 12 and 22 and are changed in color by the applied electric current. The electrolyte 50 for ion conduction and the sealing material 40 for sealing the electrolyte layer 50, .

The electrolyte 50 may be a solid electrolyte deposited on the electrochromic material layers 31 and 32 or a liquid electrolyte dispersed therein.

Unlike a liquid electrolyte, a solid electrolyte is environmentally friendly because it does not have problems such as leakage of a liquid. It is excellent in stability of an electrochromic device, and can be thinned and processed in a film form. On the other hand, there is a disadvantage that it is difficult to commercialize a proton or a lithium ion due to a slow diffusion of ion and a low ion conductivity to delay the electrochromic reaction and low performance.

The liquid electrolyte has a disadvantage in that the organic solvent is volatilized and depleted, there is a liquid leakage problem in manufacturing the device, the decoloration rate is slow, and the organic material is easily decomposed when the coloring-decoloring is repeated. Further, it is difficult to maintain the stability of the product due to side reaction with the element constituting material or volume change due to polymerization, and it is disadvantageous in that it can not be made thin and can not be processed in a film form. In order to solve this problem, U.S. Patent No. 6,667,825 discloses a liquid electrolyte including an ionic liquid and improved stability and lifetime. However, since an ionic liquid is used as a liquid electrolyte, electrolyte leakage, It is still difficult to apply to film-type processing. In addition, U.S. Patent No. 5,872,602 discloses an electrolyte which solves problems of depletion and decomposition of an electrolyte including an aluminum chloride-1-ethyl-3-methylimidazolium chloride ("AlCl3-EMICl") ionic liquid. In case of exposure to a small amount of water or oxygen, toxic gas is released and reactivity with an organic-inorganic compound added in a small amount in the electrolyte is very high. In addition, the liquid electrolyte is disadvantageous in that it is difficult to maintain the stability of the product due to side reaction with the constituent material or volume change due to polymerization, and thinning and processing in the form of a film is impossible.

Patent Document 1: U.S. Patent No. 6,667,825 (Dec. 23, 2003). Patent Document 2: U.S. Patent No. 5,872,602 (Feb.

It is another object of the present invention to provide a gel polymer electrolyte composition which can easily control the reaction rate and curing degree during polymerization and can improve ionic conductivity.

Another object of the present invention is to provide a gel polymer electrolyte composition having both excellent curability and ionic conductivity and improved permeability.

Another object of the present invention is to provide an electrochromic device including the gel polymer electrolyte composition and having improved performance.

1. A gel polymer electrolyte composition comprising a tetrafunctional (meth) acrylate compound represented by the following general formula (1) or (2), an ionic liquid, a photopolymerization initiator and a metal salt:

Wherein R is an alkanetetrayl group having 1 to 10 carbon atoms and is substituted or unsubstituted with a hydroxy group and R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from the group consisting of an alkyl group having 1 to 5 carbon atoms An alkylene group, and R ₅ , R ₆ , R ₇ , R ₈ Are independently of each other hydrogen or a methyl group),

(Wherein R ₁₁ is an alkylene group having 1 to 5 carbon atoms which may or may not contain oxygen, and four of R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ are (meth) acrylate groups And m, n, o, p, q and r are independently an integer of 1 to 5), and the other two are independently hydrogen, a hydroxyl group or an alkyl group having 1 to 5 carbon atoms.

2. The tetrafunctional acrylate-based compound according to 1 above, wherein the tetrafunctional acrylate compound is at least one selected from the group consisting of pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, di (trimethylol propane) Tetra (meth) acrylate, and dipentaerythritol tetra (meth) acrylate.

3. The gel polymer electrolyte composition according to 1 above, wherein the tetrafunctional (meth) acrylate-based compound is contained in an amount of 5 to 30% by weight based on the total weight of the composition.

4. The gel polymer electrolyte composition according to 1 above, wherein the ionic liquid is a compound in which anion is ionically bound to a cation containing at least one nitrogen atom.

5. The process of claim 1 wherein the ionic liquid is selected from the group consisting of ammonium, imidazolium, oxazolium, piperidinium, pyridinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolinium, Thiazolium, and triazolium, which may be substituted with an alkyl group having 1 to 9 carbon atoms or a cation substituted or unsubstituted with a phenyl group and a cation selected from the group consisting of F ^- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , (CN _{^{) 2 N -, BF 4 -}} , ClO 4 -, RSO 3 - (R is an alkyl group or a phenyl group having a carbon number of 1-9), RCOO ^- (R is an alkyl group or a phenyl group having a carbon number of ^{_{1-9), PF 6 -, (}} CF ^{_{3) 2 PF 4 -, (}} CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, (CF 3 SO 3 -) 2, ^{_{(CF 2 CF 2 SO 3 -}} ) 2, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 3) 2 N -, (CF 3 SO 2) (CF 3 CO) N -, CF 3 CF ^{_{2 (CF 3) 2 CO -}} , (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 COO ^- , C ₃ F ₇ COO ^- , CF ₃ SO ₃ ^- and C ₄ F ₉ SO ₃ ^- Wherein the anion is selected from the group consisting of anions and anions.

6. The gel polymer electrolyte composition according to 1 above, wherein the metal salt is an alkali metal salt.

7. In the first place, the metal salt is Li ^+, Na ^+, K ⁺ and Cs ⁺ and cations selected from the group consisting ^{of, F -, Cl -, Br} -, I -, NO 3 -, (CN) 2 N ^- , BF ₄ ^- , ClO ₄ ^- , RSO ₃ ^- (R is an alkyl group having 1-9 carbon atoms or a phenyl group), RCOO ^- (R is an alkyl group having 1-9 carbon atoms or a phenyl group), PF ₆ ^- , AsF ₆ ^{- _{6 -, (CF 3) 2}} PF 4 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, (CF 3 SO _{^{3 -) 2, (CF 2}} CF 2 SO 3 -) 2, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 3) 2 N -, (CF 3 SO 2) (CF 3 CO) N _{^{-, CF 3 CF 2 (CF}} 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO A combination of anions selected from the group consisting of ₃ ^- , CF ₃ COO ^- , C ₃ F ₇ COO ^- , CF ₃ SO ₃ ^- and C ₄ F ₉ SO ₃ ^- .

8. In the first place, the metal salt is LiPF _6, LiClO _4, or a mixture thereof a gel polymer electrolyte composition.

9. The gel polymer electrolyte composition according to 1 above, wherein the metal salt is contained so that the concentration of the cation in the metal salt is 0.5 to 1.5 mol / L.

10. An electrochromic device comprising a first electrode, a second electrode, an electrochromic material, and an electrolyte formed by photo-curing of the gel polymer electrolyte composition of any one of items 1 to 9 above.

11. The electrochromic device of claim 10, wherein the electrolyte is in-situ polymerized between the first and second electrodes.

The gel polymer electrolyte composition of the present invention has improved ionic conductivity and has a high response speed when applied to an electrochromic device, thereby securing excellent electrochromic properties.

In addition, the gel polymer electrolyte composition of the present invention has a high polymerization reaction rate and is easy to control the degree of curing, so that appropriate mechanical strength can be imparted.

In addition, the gel polymer electrolyte composition of the present invention has excellent curability and ion conductivity, so that not only excellent mechanical strength and electrochromic characteristics can be secured, but also high permeability can be maintained.

In addition, the gel polymer electrolyte composition of the present invention is excellent in the stability of the product because its retention performance is excellent even when the cycle of coloring / decoloring is repeated.

In addition, the gel polymer electrolyte composition of the present invention has no problems of depletion of electrolyte and side reaction between electrolyte leakage and element constituent materials, and it is possible to manufacture devices on various substrates, It can be simplified.

1 is a cross-sectional view of a general electrochromic device.

The present invention includes a tetrafunctional (meth) acrylate-based compound represented by the general formula (1) or (2), an ionic liquid, a photopolymerization initiator and a metal salt to improve the degree of curing and ionic conductivity, And an electrochromic device using the gel polymer electrolyte composition.

Hereinafter, the present invention will be described in detail.

The gel polymer electrolyte composition of the present invention is characterized by containing a tetrafunctional (meth) acrylate compound represented by Chemical Formula 1 or Chemical Formula 2, an ionic liquid, a photopolymerization initiator, and a metal salt. In the present invention, (meth) acrylate refers to acrylate, methacrylate, or both.

In the present invention, a tetrafunctional (meth) acrylate-based compound represented by Chemical Formula 1 or Chemical Formula 2 is used as a compound capable of forming a gel polymer electrolyte by participating in a polymerization reaction by photocuring together with a polymerization initiator have. When the number of polymerizable groups is 2 to 3, the degree of curing is decreased. When the number of polymerizable groups is 5 or more, there is a problem that the degree of curing is excellent but the ion conductivity is lowered.

Accordingly, the present invention solves the above-mentioned problems by using a tetrafunctional (meth) acrylate compound, and particularly relates to a process for producing a tetrafunctional (meth) acrylate compound represented by Chemical Formula 1 or Chemical Formula 2 having four functional (meth) (Meth) acrylate-based compound, it is possible to further improve the ionic conductivity and to control the degree of curing as well as to reduce the shrinkage and expansion of the volume with a high reaction rate during polymerization, and to provide a gel polymer electrolyte Lt; / RTI >

[Chemical Formula 1]

Wherein R is an alkanetetrayl group having 1 to 10 carbon atoms and is substituted or unsubstituted with a hydroxy group and R ₁ , R ₂ , R ₃ and R ₄ are each independently of the other alkyl having 1 to 5 carbon atoms a _{group, R 5, R 6, R} 7, R 8 Are independently of each other hydrogen or a methyl group.

(2)

In the formula, R ₁₁ is an alkylene group having 1 to 5 carbon atoms which may or may not contain oxygen, and four of R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ are (meth) M, n, o, p, q, and r are independently integers of 1 to 5;

Examples of the tetrafunctional (meth) acrylate compound represented by the formula (1) include pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (Meth) acrylate and ethoxylated pentaerythritol tetra (meth) acrylate may be used alone or in combination of two or more.

Examples of the tetrafunctional (meth) acrylate compound represented by formula (2) include di (trimethylol propane) tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, , And dipentaerythritol tetra (meth) acrylate can be preferably used.

The tetrafunctional (meth) acrylate-based compound represented by the formula (1) or (2) is preferably contained in an amount of 5 to 30% by weight, more preferably 5 to 15% by weight based on the total weight of the gel polymer electrolyte composition of the present invention . When the content is less than 5% by weight, the formation of the gel polymer electrolyte may be weak and it may be difficult to impart proper mechanical strength. When the content is more than 30% by weight, the effect of improving the ion conductivity may be insignificant and the electrochromic rate may be lowered.

A small amount of a vinyl compound can be mixed and used as a compound capable of forming a gel polymer electrolyte by photocuring together with a tetrafunctional (meth) acrylate compound represented by the above formula (1) or (2).

The kind of the vinyl compound is not particularly limited, and examples thereof include (meth) acrylonitrile, methyl (meth) acrylate, vinyl ester compound, vinyl chloride, vinylidene chloride, acrylamide, tetrafluoroethylene, vinyl acetate, Ketone, ethylene, styrene, methylstyrene, p-methoxystyrene, p-cyanostyrene, and polyethylene glycol acrylate. These may be used alone or in combination of two or more. The vinyl compound may be used in a small amount insofar as the yellowing caused by the polymerization initiator does not occur.

BACKGROUND ART An ionic liquid is an ionic compound which is formed by ionic bonding of a cation and an anion, and is an ionic salt having a property of being present as a liquid at a temperature of 100 DEG C or lower. In particular, in the present invention, the ionic liquid preferably contains at least one nitrogen atom. The free radicals generated by the nitrogen atom promote the rate of polymerization reaction for gel polymer electrolyte formation to suppress shrinkage and expansion and impart appropriate mechanical strength.

Ionic liquids are non-volatile, non-flammable, have high thermal stability and ionic conductivity, have a high polarity, and have unique characteristics of dissolving inorganic and organic metals and maintaining liquid state at a wide range of temperatures. It is a substance that is being studied as a next generation environmentally friendly solvent.

Examples of the cation constituting the ionic liquid include ammonium, imidazolium, oxazolium, piperidinium, pyran, etc. represented by the general formulas (a) to (n) Pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolinium, pyrrolium, and the like. , Thiazolium, triazolium, and the like.

(Wherein R ₂₀ to R ₂₅ are independently of each other hydrogen, an alkyl group having 1 to 9 carbon atoms or a phenyl group).

The anion constituting the ionic liquid includes F ^- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , (CN) ₂ N ^- , BF ₄ ^- , ClO ₄ ^- , RSO ₃ ^- -9 alkyl or phenyl), RCOO ^- (wherein, R is an alkyl group or a phenyl group having a carbon number of ^{_{1-9), PF 6 -, (}} CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3 ) ₄ PF ₂ ^- , (CF ₃ ) ₅ PF ^- , (CF ₃ ) ₆ P ^- , (CF ₃ SO ₃ ^- ) ₂ , (CF ₂ CF ₂ SO ₃ ^- ) ₂ , (C ₂ F ₅ SO ₂ ) _{^{2 N -, (CF 3 SO}} 3) 2 N -, (CF 3 SO 2) (CF 3 CO) N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, ^{_{(SF 5) 3 C -,}} (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 COO -, C 3 F 7 COO -, CF 3 SO 3 -, C 4 F ₉ SO ₃ ^- , and the like.

The ionic liquid may be contained in an amount of preferably 1 to 10% by weight, more preferably 5 to 10% by weight, based on the total weight of the gel polymer electrolyte composition of the present invention. If the content is less than 1% by weight, the effect of improving the ionic conductivity may be insignificant and the rate of electrochromatography may be lowered. If the content is more than 10% by weight, polymer electrolyte formation may be weak and appropriate mechanical strength may be difficult to impart.

The polymerization initiator is for improving the curing reaction efficiency of the gel polymer electrolyte composition, and includes a photo-radical generator which generates an active radical by light irradiation and an acid generator which generates an acid, At the same time. These may be used alone or in combination of two or more.

The polymerization initiator serves only to facilitate the polymerization of the compound having a polymerizable group, but does not constitute a component of the polymer. On the other hand, as a component for forming a gel, a gelling agent is introduced in the art, and the gelling agent itself becomes a constituent of the substance to be gelled. When a gelling agent is used instead of the polymerization initiator in the present invention, the polymerization time is prolonged, the life of the electrochromic device is lowered, and the transmittance is lowered.

Examples of the photo radical generator include acetophenone, benzoin, benzophenone, thioxanthone and triazine compounds.

Examples of the acetophenone-based compounds include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-2-methyl- 1- [2- (2-hydroxyethoxy ) Phenyl] propan-1-one and its oligomers, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan- 2-dimethylamino-1- (4-morpholinophenyl) butan-1-one.

Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the benzophenone compound include benzophenone, methyl o-benzoyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3 ', 4,4'- Oxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, and the like.

Examples of the thioxanthone compound include 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1- City Oak Mountain, and the like.

Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (Methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6-piperonyl-1,3,5-triazine, 2,4- Methyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- 2- (furan-2-yl) ethenyl] -1,3,5-triazine, 2,4,6-trichloromethyl- Bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine, 2,4- - [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

Examples of the photo radical generator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenyl- It is also possible to use, for example, bis-imidazole, 10-butyl-2-chloroacridone, 2-ethyl anthraquinone, 9,10-phenanthrenequinone, camphorquinone, methylphenylglyoxylate, benzyldimethylketal, have.

Examples of the acid generator include 4-hydroxyphenyldimethylsulfonium p-toluenesulfonate, 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium p-toluenesulfonate, 4-acetic acid Triphenylsulfonium hexafluoroantimonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium Onium salts such as hexafluoroantimonate; Nitrobenzyl tosylate, benzoin tosylate, and the like.

Examples of the polymerization initiator include commercially available products such as Opethoma (Asahi Kogyo Co.), Irgacure, OXE-01 (Ciba), Seid SI-60L, UVI-6990 (Union Carbide), BBI-1C3, MPI -103, TPS-103, DTS-103, NAT-103 and NDS-103 (Midori Chemical).

The polymerization initiator is preferably contained in an amount of 0.1 to 2 parts by weight (based on the solid content) based on 10 parts by weight (based on solid content) of the tetrafunctional (meth) acrylate compound according to the present invention. When the content is less than 0.1 part by weight, the formation of the gel polymer electrolyte is insignificant, while when it is more than 2 parts by weight, the ion conductivity improving effect may not be large.

The metal salt is used to provide metal ions to the gel polymer electrolyte composition. The metal salt is inserted or removed in the electrochromic material to change the oxidation number of the transition metal contained in the electrochromic material, thereby changing the optical property of the electrochromic material itself .

As the metal salt, it is preferable to use an alkali metal salt. More specifically, a cation selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ and Cs ⁺ and a cation selected from the group consisting of F ^- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , (CN) ₂ N ^- , BF ₄ ^{- _{ClO 4 -, RSO 3 -,}} RCOO (R is an alkyl group or a phenyl group having a carbon number of 1-9) ^-, PF ₆ (R is an alkyl group or a phenyl group having a carbon number of _{^{1-9) -, AsF 6 -,}} SbF 6 -, (CF 3 ^{_{) 2 PF 4 -, (CF}} 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, (CF 3 SO 3 -) 2, ( ^{_{CF 2 CF 2 SO 3 -)}} 2, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 3) 2 N -, (CF 3 SO 2) (CF 3 CO) N -, CF 3 CF 2 ^{_{(CF 3) 2 CO -,}} (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 COO ^- , C ₃ F ₇ COO ^- , CF ₃ SO ₃ ^- and C ₄ F ₉ SO ₃ ^- are preferable.

In particular, when an inorganic metal such as WO ₃ or NiO is used as an electrochromic material of an electrochromic device, it is preferable to use an alkali metal salt containing a lithium cation such as LiClO ₄ , LiAsF ₆ , LiSbF ₆ , LiPF ₆ or LiBF ₄ And more preferably LiPF ₆ , LiClO ₄ or a mixture thereof.

The metal salt can be used by appropriately adjusting the content thereof according to the composition of the electrolyte composition and the kind of the electrochromic material without affecting other components of the gel polymer electrolyte composition. The metal salt is preferably contained so that the concentration of the cation in the metal salt is 0.5 to 1.5 mol / L based on the total content of the gel polymer electrolyte composition. When the concentration of the cation of the metal salt is less than 0.5 mol / L, the solubility in the gel polymer electrolyte composition is good, but the number of free ions that can be conducted is small and it is difficult to exhibit sufficient performance as an electrolyte of the electrochromic device. If the concentration is more than 1.5 mol / L, dissolution of the gel polymer electrolyte composition is not performed well and ion-paring is formed. That is, after the ion is dissolved, In the case of ion pair or ion aggregation, migration is impossible and consequently, the number of free ions is reduced and the conductivity is lowered.

The metal salt is dissolved in an organic solvent and added to the gel polymer electrolyte composition. Examples of the organic solvent include organic solvents used in the art such as propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethylsulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (EMC), gamma-butyrolactone -Butyrolactone) may be used alone or in admixture of two or more, but the present invention is not limited thereto. The organic solvent in which the metal salt is dissolved occupies the majority of the electrolyte composition and is included as a balance with respect to the content of the components of the gel polymer electrolyte composition described above.

The method for producing the gel polymer electrolyte using the gel polymer electrolyte composition of the present invention is not particularly limited. For example, it can be produced by an in-situ polymerization reaction by photocuring in an electrode. In this case, the in-situ polymerization is a method in which the gel polymer electrolyte composition is injected between the two electrodes and then polymerized, which is easier to handle than controlling the polymerized electrolyte, which is useful in the production of an electrochromic device. In addition, there is a good advantage of wetting and contact between the gel polymer electrolyte and the electrode.

Polymerization conditions of the gel polymer electrolyte by photo-curing are not particularly limited, and can be carried out at a polymerization time of 10 minutes or less, for example, at a normal light irradiation dose.

The electrochromic device of the present invention is characterized by comprising a first electrode, a second electrode, an electrochromic material and an electrolyte formed by photocuring of the gel polymer electrolyte composition.

The first electrode and the second electrode may have a structure in which a transparent conductive layer is formed on a substrate.

The substrate and the transparent conductive layer are not particularly limited as long as they are well known in the art. Examples of the conductive material for forming the transparent conductive layer include ITO (indium doped tin oxide), ATO (antimony doped tin oxide), FTO (fluorine doped tin oxide), and the like. , Indium doped zinc oxide (IZO), and zinc oxide (ZnO). A transparent conductive layer can be formed on the substrate by depositing a conductive material by a known method such as sputtering, electron beam evaporation, chemical vapor deposition, or sol-gel coating.

Examples of the electrochromic material include, but are not limited to, inorganic oxides such as WO ₃ , Ir (OH) x, MoO ₃ , V ₂ O ₅ , TiO ₂ and NiO; Conductive polymers such as polypyrrole, polyaniline, polyazulene, polypyridine, polyindole, polycarbazole, polyazine, and polythiophene; Organic coloring materials such as violon, anthraquinone, phenothiazine, and the like.

The method of laminating the electrochromic material on the electrode is not particularly limited as long as the thin film can be formed at a constant height from the basal plane along the surface profile. For example, a vacuum deposition method such as sputtering can be mentioned.

Of the electrochromic materials, WO ₃ is a substance that is colored by a reduction reaction, and NiO is a substance that is colored by an oxidation reaction. The electrochemical mechanism by which electrochromism occurs in an electrochromic device containing such an inorganic metal oxide is explained as shown in the following reaction formula (1). Specifically, when a voltage is applied to the electrochromic device, the proton (H ⁺ ) or lithium ion (Li ⁺ ) contained in the electrolyte is inserted or eliminated as an electrochromic material depending on the polarity of the electric current. The change in the oxidation number of the transition metal contained in the electrochromic material changes the optical characteristic of the electrochromic material itself, for example, the transmittance (color).

[Reaction Scheme 1]

WO ₃ (transparent) + xe + xM ↔ MxWO ₃ (dark blue)

(Wherein M is a proton or an alkali metal cation such as Li ⁺ ; x is any integer).

The electrochromic device thus constructed may be manufactured according to a conventional method known in the art, for example, (a) preparing a first electrode and a second electrode; (b) injecting the gel polymer electrolyte composition according to the present invention between the prepared first electrode and the second electrode, and then sealing the gel polymer electrolyte composition; And (c) polymerizing the injected electrolyte composition to form a gel polymer electrolyte.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example  1-9 and Comparative Example  1-7

<Gel Polymer  Electrolyte composition>

A gel polymer electrolyte composition was prepared with the compositions shown in Table 1 below.

4-functional (meth) acrylate Ionic liquid Photopolymerization initiator Gelling agent Liquid electrolyte A-1 A-2 A-3 A-4 A-5 B-1 B-2 C-1 D-1 Example 1 10 3 0.5 86.5 Example 2 10 5 0.5 84.5 Example 3 10 One 0.5 88.5 Example 4 10 3 0.5 86.5 Example 5 10 3 0.5 86.5 Example 6 20 3 0.5 76.5 Example 7 4 3 0.5 92.5 Example 8 10 0.5 0.5 89.0 Example 9 10 3 0.5 86.5 Comparative Example 1 10 3 0.5 86.5 Comparative Example 2 10 3 0.5 86.5 Comparative Example 3 10 3 0.5 86.5 Comparative Example 4 10 3 0.5 86.5 Comparative Example 5 10 3 0.5 86.5 Comparative Example 6 10 0.5 89.5 Comparative Example 7 10 0.5 89.5 A-1: Pentaerythritol tetraacrylate (tetrafunctional)
A-2: Ditrimethylolpropane tetra (meth) acrylate (tetrafunctional)
A-3: Ethoxylated pentaerythritol tetra (meth) acrylate (tetrafunctional)
A-4: Hexyl acrylate (monofunctional)
A-5: dipentaerythritol pentaacrylate (pentafunctional)
B-1: 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, [BMI-TFSI]
B-2: Aluminum chloride-1-ethyl-2-methylimidazolium chloride [AlCl3-EMIC]
C-1: OXE-01 (1,2-Octanedione, 1- [4- (phenylthio) phenyl] -, 2- (O-benzoyloxime)
D-1: 1-butylpyridinium tetrafluoroborate (PyBF4)
Liquid electrolyte: 1M LiPF6 in EC (3) / PC (2) / DEC (5)

&Lt; Electrochromic device &

An ITO transparent conductive layer was deposited on the glass substrate to a thickness of 150 nm, and a 200 nm thick WO ₃ electrochromic material thin film was formed thereon by a sputtering method to prepare a working electrode. Further, a counter electrode having a NiO thin film with a thickness of 300 nm was manufactured in the same manner as the working electrode. Except for a part of the rim of the working electrode and the counter electrode (electrolyte injection hole), a UV sealant was used to produce an electrochromic device intermediate without electrolyte. The gel polymer electrolyte composition prepared according to the above Table 1 was injected into the prepared intermediate, the injection port was sealed with a UV sealing material, and the resultant was irradiated with light in an ultraviolet (UV) exposure apparatus for 1 minute to prepare an electrochromic device by in- .

Test Example

The physical properties of the polymer electrolyte composition and the electrochromic device prepared in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

One. Polymer  Ionic conductivity of electrolyte

Ion conductivity was measured using a conductivity meter (Inolab multi 740).

<Evaluation Criteria>

?: Ionic conductivity> 10 ^-4 S / cm

?: 10 ^-5 S / cm? Ion conductivity? 10 ^-4 S / cm

×: 10 ^-5 S / cm> ion conductivity

2. Polymerization time

The time at which curing of the gel polymer electrolyte composition is completed using an infrared spectrometer (FT-IR spectrum), for example, the change in the degree of double bond cleavage and the change in the transmittance (T) of the polymer electrolyte according to polymerization is measured, Respectively.

<Evaluation Criteria>

◎: polymerization time ≤ 60 seconds

○: 60 seconds <polymerization time ≤ 120 seconds

?: 120 seconds <polymerization time? 180 seconds

×: 180 sec <polymerization time

3. Product stability

The stability of the product was evaluated by measuring the number of times the electrochromic device was maintained by measuring the cycle of the electrochromic device (coloration 3V 20 sec / decoloration -3V 20 sec) using a response speed meter.

<Evaluation Criteria>

&Amp; cir &amp;: 1000 times &amp;le; number of times the electrochromism is maintained (very good).

○: 500 or more ≦ number of times the electrochromism is maintained <1000 times (good).

?: The number of times the electrochromism is maintained < 500 (normal).

X: No electrochromism (poor).

4. Electrochromism (staining / Decoloration ) Transmittance (%)

The electrochromic device (coloring / decoloring) test of the electrochromic device was conducted for 2 hours or longer, and the transmittance at 400 nm was measured. At this time, it was considered that the transmittance at the time of coloring was 37% or less, and the larger the difference in the transmittance value at the time of coloring / quenching, the better.

Ion conductivity  Polymerization time Product stability  Transmittance (coloring / decoloring) Example 1 ◎ ◎ ◎ 30/71 Example 2 ◎ ◎ ◎ 31/70 Example 3 ◎ ◎ ○ 30/69 Example 4 ○ ◎ ◎ 34/69 Example 5 ○ ○ ◎ 31/71 Example 6 ○ ○ ○ 33/72 Example 7 ○ △ ○ 32/69 Example 8 ◎ ◎ △ 31/71 Example 9 ○ ○ △ 35/65 Comparative Example 1 ○ △ △ 46/62 Comparative Example 2 ○ △ × 45/64 Comparative Example 3 △ △ △ 44/71 Comparative Example 4 △ △ × 48/71 Comparative Example 5 ○ △ × 46/71 Comparative Example 6 ○ ○ × 47/71 Comparative Example 7 ○ × × 46/68

As shown in Table 2, the gel polymer electrolytes of Examples 1 to 9 including the tetrafunctional (meth) acrylate-based compound represented by Chemical Formula 1 or Chemical Formula 2, an ionic liquid, a polymerization initiator, Showed high ionic conductivity, promoted polymerization reaction according to photo - curing, easily controlled the degree of curing, and also had excellent transparency according to electrochromism. Particularly, when the content of the tetrafunctional (meth) acrylate compound and the ionic liquid is included in the preferred range of the present invention, it is more effective in terms of ion conductivity, polymerization time, and product stability, and is particularly effective in terms of shortening the polymerization time . The use of an alkali metal salt as a metal salt was more effective in terms of product stability than a non-alkali metal salt.

On the other hand, in the case of the comparative examples, it can be seen that the difference in transmittance in coloring / coloring as a whole is remarkably smaller than those in the examples.

In addition, in Comparative Examples 1 and 2 using a conventional monofunctional acrylate compound, the polymerization time was long and the polymerization reaction was difficult to control, and shrinkage and swelling occurred due to polymerization, resulting in poor product stability. In Comparative Examples 3 and 4 using the pentafunctional acrylate compound, the curing performance was excellent, but the ion conductivity was low and the permeability was remarkably low. In Comparative Example 6 in which an ionic liquid was not used, shrinkage and expansion occurred due to polymerization, and the stability of the product was deteriorated. Comparative Examples 5 and 7 using a gelling agent instead of the polymerization initiator showed a very long polymerization time and a low degree of curability and a markedly low permeability performance. Further, in Comparative Example 7 using a monofunctional acrylate compound, It can be seen that it is further lowered.

10: first electrode 11: substrate for first electrode
12: conductive layer for second electrode 20: second electrode
21: substrate for a second electrode 22: conductive layer for a second electrode
31: Electrochromic material layer of the first electrode
32: Electrochromic material layer of the second electrode
40: Seal material 50: Electrolyte

Claims (11)

A tetrafunctional (meth) acrylate compound represented by the following general formula (1) or (2), an ionic liquid, a photopolymerization initiator, and a liquid electrolyte in which a metal salt is dissolved in an organic solvent,
The organic solvent may be selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, Wherein the gel polymer electrolyte composition comprises at least one selected from the group consisting of tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (EMC) and gamma-butyrolactone :
[Chemical Formula 1]

Wherein R is an alkanetetrayl group having 1 to 10 carbon atoms and is substituted or unsubstituted with a hydroxy group and R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from the group consisting of an alkyl group having 1 to 5 carbon atoms R ₅ , R ₆ , R ₇ and R ₈ independently of one another are hydrogen or a methyl group),
(2)

(Wherein R ₁₁ is an alkylene group having 1 to 5 carbon atoms which may or may not contain oxygen, and four of R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ are (meth) acrylate groups And m, n, o, p, q and r are independently an integer of 1 to 5), and the other two are independently hydrogen, a hydroxyl group or an alkyl group having 1 to 5 carbon atoms.
The tetrafunctional acrylate compound according to claim 1, wherein the tetrafunctional acrylate compound is at least one selected from the group consisting of pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, di (trimethylolpropane) tetra (Meth) acrylate and dipentaerythritol tetra (meth) acrylate.
The composition according to claim 1, wherein the tetrafunctional (meth) acrylate compound is contained in an amount of 5 to 30 wt% based on the total weight of the composition, the ionic liquid is contained in an amount of 1 to 10 wt% Is contained in an amount of 0.1 to 2 parts by weight based on the solid content based on 10 parts by weight of the solid content of the functional (meth) acrylate compound,
Wherein the organic solvent is contained in a remaining amount.
The gel polymer electrolyte composition according to claim 1, wherein the ionic liquid is a compound in which anion is ionically bound to a cation containing at least one nitrogen atom.
The method of claim 1, wherein the ionic liquid is selected from the group consisting of ammonium, imidazolium, oxazolium, piperidinium, pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolinium, , thiazolium, and is selected from the group consisting of a triazolium these are substituted by an alkyl group or a phenyl group having a carbon number of 1-9 or unsubstituted ^{cations, F -, Cl -, Br} -, I -, NO 3 -, (CN) 2 ^{_{N -, BF 4 -, ClO}} 4 -, RSO 3 -, RCOO (R is an alkyl group or a phenyl group having a carbon number of 1-9) ^-, PF ₆ (R is an alkyl group or a phenyl group having a carbon number of 1-9) ^-, (CF _{3) ^{2 PF 4 -, (CF 3}} ) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, (CF 3 SO 2) 2 N -, ( _{CF 3 CF 2 SO 3) 2} N -, (C 2 F 5 SO 2) 2 N -, (CF 3 SO 2) (CF 3 CO) N -, CF 3 CF 2 (CF 3) 2 CO -, ( ^{_{CF 3 SO 2) 2 CH -}} , (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 COO -, C 3 F 7 COO -, CF ₃ SO ₃ ^- and C ₄ F ₉ SO ₃ ^- Anions, and anions.
The gel polymer electrolyte composition according to claim 1, wherein the metal salt is an alkali metal salt.
The method of claim 1, wherein the metal salt comprises a cation selected from the group consisting of Li ⁺ , Na ⁺ , K ^+, and Cs ^{+
F -, Cl -, Br -} , I -, NO 3 -, (CN) 2 N -, BF 4 -, ClO 4 -, RSO 3 -, RCOO (R is an alkyl group or a phenyl group having a carbon number of 1-9) ^- ( R is an alkyl group or a phenyl group having a carbon number of ^{_{1-9), PF 6 -, AsF}} 6 -, SbF 6 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 - ^{_{, (CF 3) 5 PF -}} , (CF 3) 6 P -, (CF 3 SO 3 -) 2, (CF 2 CF 2 SO 3 -) 2 N 2, (C 2 F 5 SO 2) -, ( ^{_{CF 3 SO 3) 2 N -}} , (CF 3 SO 2) (CF 3 CO) N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 a ^{_{- C -, (CF 3 SO}} 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 COO -, C 3 F 7 COO -, CF 3 SO 3 - and C ₄ F ₉ SO ₃ &Lt; / RTI &gt; wherein the anion is selected from the group consisting of anions.
The gel polymer electrolyte composition according to claim 1, wherein the metal salt is LiPF ₆ , LiClO ₄ or a mixture thereof.
The gel polymer electrolyte composition according to claim 1, wherein the metal salt is contained so that the concentration of the cation in the metal salt is 0.5 to 1.5 mol / L.
An electrochromic device comprising a first electrode, a second electrode, an electrochromic material, and an electrolyte formed by photocuring of the gel polymer electrolyte composition of any one of claims 1 to 9.
The electrochromic device according to claim 10, wherein the electrolyte is in-situ polymerized between the first and second electrodes.

Images