KR100421356B1 - Solid polymer electrolyte, its preparation and electrochromic device comprising the same - Google Patents

Abstract

The present invention relates to a polymer matrix obtained by photocuring a mixture containing or not containing polyethylene glycol having an acrylate or methacrylate group, polyethylene glycol having an acrylic or methacrylic reactive group, a low molecular weight polyethylene oxide derivative and a photoinitiator; The present invention relates to a solid polymer electrolyte thin film comprising titanium dioxide and an alkali salt dispersed in the polymer matrix, a method for preparing the same, and an electrochromic device using the same. The present invention also relates to a composition for preparing the solid polymer electrolyte thin film. According to the present invention, a conductive film having a white color and having an ionic conductivity of about 8 × 10 ⁻³ S / cm at room temperature is provided, and an electrochromic device having a response speed of several seconds or less is provided.

Description

Solid polymer electrolyte, method for manufacturing same, and electrochromic device including the same {SOLID POLYMER ELECTROLYTE, ITS PREPARATION AND ELECTROCHROMIC DEVICE COMPRISING THE SAME}

The present invention provides a solid polymer electrolyte prepared by photocuring from a solid polymer electrolyte and a method for preparing the same, specifically, a composition containing titanium dioxide, and more particularly, a method in which titanium dioxide used in an electrochromic device is dispersed. The present invention relates to a solid polymer electrolyte prepared by photocuring from a composition and a method for producing the same.

An electrochromic device (ECD-ElectroChromic Device) is composed of a transparent electrode / electrochromic material thin film / electrolyte / transparent (or translucent electrode), and when the electric field is applied, the color of the electrochromic material is changed by electrochemical oxidation / reduction reaction. As a device using the principle, an electrolyte that plays a role of transferring charge between both electrodes is essential.

The electrolyte used in the conventional electrochromic device can be largely represented by an electrolyte in the form of an aqueous solution, an electrolyte in the form of an inorganic hydrate, and a solid polymer electrolyte. Examples of the electrolyte in the form of an aqueous solution include 1M H ₂ SO ₄ aqueous solution, 1M LiOH aqueous solution, and 1M LiClO. to ₄ can be exemplified by solution, 1M aqueous solution of KOH or the like, an inorganic hydrate, and the like _{HUP 2 PO 4 · 4H 2 O} , Ta 2 O 5 · 3.92H 2 O, Sb 2 O 5 · 4H 2 O. The electrolyte in the form of an aqueous solution, which has been widely used as an electrolyte for an electrochromic device, has an advantage of having good ion conductivity, but caused various side effects due to leakage of the aqueous solution during fabrication of the device.

Unlike the liquid electrolyte used previously, the solid polymer electrolyte is environmentally friendly, thinner, and can be manufactured in the form of a film because there are no problems such as leakage of the solution. The research is being actively conducted due to the advantage of giving a memory effect.

Solid polymer electrolytes capable of transferring ions in a solid solid state can be roughly divided into an intrinsic solid polymer electrolyte and a hybrid solid polymer electrolyte. Because the hybrid solid polymer electrolyte contains an organic solvent, ionic conductivity at room temperature is high, but strength is weak, and there are problems such as volatilization of the organic solvent and reactivity of the added organic solvent. In contrast, intrinsic solid polymer electrolytes have an advantage of not including an organic solvent, and examples thereof include poly-AMPS, poly (VAP), and modified PEO / LiCF ₃ SO ₃ . However, these electrolytes did not provide satisfactory results with very low ionic conductivity, which is related to the response speed of the electrochromic device.

Accordingly, an object of the present invention is to solve the above problems and to provide a solid polymer electrolyte having high conductivity and no reactivity with an electrochromic material.

It is another object of the present invention to prepare a titanium dioxide dispersed UV curable solid polymer electrolyte.

Still another object of the present invention is to provide a method for preparing the UV curable solid polymer electrolyte in which the titanium dioxide is dispersed.

Still another object of the present invention is to provide an electrochromic device including the ultraviolet curable solid polymer electrolyte in which the titanium dioxide is dispersed.

Still another object of the present invention is to provide a composition used in the preparation of the ultraviolet curable solid polymer electrolyte in which the titanium dioxide is dispersed.

1 shows a schematic diagram of a solid polymer electrolyte according to the present invention.

Figure 2 is a graph showing the ionic conductivity at room temperature of the solid polymer electrolyte according to the present invention.

3 is a cross-sectional view of an electrochromic device including the solid polymer electrolyte of the present invention.

The present invention includes a polyethylene glycol having an acrylate group or a methacrylate group of formula (1), a polyethylene glycol having an acrylic or methacrylic reactive group of the formula (2), a low molecular weight polyethylene oxide derivative of the formula (3) and an ultraviolet initiator It relates to a polymer matrix obtained by photocuring a mixture that does not contain, a solid polymer electrolyte (thin film) comprising titanium dioxide dispersed in the polymer matrix and an alkali salt of formula (4).

A ⁺ B ^-

In Formulas 1 to 3, R ₁ is a hydrogen atom or a straight or branched chain lower alkyl group having 1 to 10 carbon atoms, R ₂ is R ₁ or a compound of Formula 5, n is 1 to 50, preferably Is an integer from 2 to 20, most preferably from 2 to 10, and m and k represent an integer from 2 to 50, preferably from 5 to 10. In Formula 4 A ⁺ represents an alkali cation, including lithium and sodium, B ^- is ^{Cl -, Br -, I -} , SCN -, ClO 4 -, CF 3 SO 3 -, N (CF 3 SO 3) ₂ ^-, BF ₄ ^- represents a ^-, PF ₆ ^- or AsF _6.

In Formula 5, the definition of R ₁ is as described above.

1 shows a schematic diagram of a solid polymer electrolyte according to the present invention, wherein the polymer matrix has a network structure, and shows that titanium dioxide is uniformly dispersed in the polymer matrix of the network structure.

The present invention also relates to a composition used in the preparation of the solid polymer electrolyte, wherein the composition is polyethylene glycol having an acrylate group or methacrylate group of Formula 1, polyethylene glycol having an acrylic or methacrylic reactive group of Formula 2 , A low molecular weight polyethylene oxide derivative of Chemical Formula 3, an alkali salt of Chemical Formula 4 and titanium dioxide. The composition of the present invention may also further comprise an ultraviolet initiator for promoting photocuring. Examples of ultraviolet initiators that can be used in the compositions of the present invention are 2,2-dimethoxy-2-phenylacetophenone, 2-methoxy-2-phenylacetone, benzyldimethyl ketal, ammonium persulfate, benzonon, ethylbenzoin Ether, isopropylbenzoin ether, α-benzoinphenyl ether, 2,2, -diethoxyacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one , 1-hydroxycyclohexylphenyl ketone, anthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, thioxanthone, isopropyl thioxanthone, chlorothioxanthone, 2,2-chlorobenzophenone, benzyl, Benzyl benzoate and benzoyl isobutyl ether are mentioned.

Hereinafter, the present invention will be described in more detail.

In the solid polymer electrolyte thin film of the present invention, the polyethyleneglycol alkylether having an acrylate group or methacrylate group of Formula 1 and the crosslinking agent of Formula 2 are used in a molar ratio of 0.1 to 1, preferably 0.1 to 0.5. . The crosslinking agent of Chemical Formula 2 is a low molecular weight compound which forms a polymer network to impart mechanical properties to the ion conductive thin film of the present invention and to reduce crystallinity of the polymer matrix. When the amount of the cross-linking agent of Formula 2 is greater than the range, the hardness of the solid polymer electrolyte thin film is high and easily broken, and when less than the range, the thin film is difficult to form.

Polyethylene oxide derivative of Formula 3 which is another component of the composition of the present invention described above is 1 to 100% by weight, preferably 20 to 70% by weight of the total weight of the composition, the alkali salt of Formula 4 is the total 1 to 50% by weight, preferably 5 to 30% by weight, most preferably 5 to 20% by weight, UV initiator is 0.1 to 10% by weight, preferably 0.1 to 5% by weight based on the total weight of the composition Each is contained in an amount of.

Titanium dioxide, which is another component of the composition of the present invention described above, is contained in an amount of 1 to 30% by volume, preferably 1 to 20% by volume, and most preferably 1 to 15% by volume, based on the total composition. According to an embodiment of the present invention, the solid polymer electrolyte containing titanium dioxide in the above range has an ionic conductivity about 10 times increased at room temperature compared to the solid polymer electrolyte containing no titanium dioxide, and has a network matrix. Due to the high refractive index of titanium dioxide dispersed within, the resulting solid polymer electrolyte thin film was found to have a white color.

The method for preparing a solid polymer electrolyte according to the present invention may include a composition of the present invention as described above using a substrate (for example, an ITO glass plate or a plastic plate, an ITO glass plate or a plastic plate coated with an electrochromic material, a chrome plate, an aluminum foil, or the like). And photocuring by applying ultraviolet light of 200 to 400 nm after coating on the substrate). The method of applying the composition onto the substrate can be accomplished by a variety of methods including bar coating, spin coating and silkscreen.

Hereinafter, the present invention will be described in more detail by the following examples, but the scope of the present invention is not limited to these examples.

Example

Example 1

2.43 g polyethylene glycol monomethacrylate monomethyl ether (molecular weight 450, manufactured by Polyscience), 0.65 g polyethylene glycol dimethacrylate (molecular weight 500, manufactured by Polyscience), 3.0 g polyethylene glycol dimethyl ether (molecular weight 250, Aldrich), 0.89 g of lithium trifluoromethanesulfonate (molecular weight 156.01, Aldrich) and 0.1 g of dimethoxyphenylacetophenone (molecular weight 256.30, Aldrich) are mixed. 0.20 g of titanium dioxide was added to 1 mL of the mixture and mixed uniformly using a mortar, and then a coating layer having a uniform thickness was formed on an ITO glass plate by a bar coating method. Solid polymer electrolyte was prepared. Ionic conductivity of the prepared solid polymer electrolyte was 9.2 × 10 ⁻³ S / cm at room temperature.

Examples 2-6

Except for changing the composition of each composition as shown in Table 1, except that the polymer thin film was prepared in the same manner as in Example 1, the ionic conductivity at room temperature of the prepared polymer thin film was measured, the results are shown in Table 1 As shown in.

In Table 1, the polymer electrolyte composition includes 2.43 g of polyethylene glycol monomethacrylate monomethyl ether (molecular weight 450, manufactured by Polyscience, Inc.), 0.65 g of polyethylene glycol dimethacrylate (molecular weight 500, manufactured by Polyscience, Inc.), 3.0 g. A mixture of polyethylene glycol dimethyl ether (molecular weight 250, Aldrich), 0.89 g lithium trifluoromethanesulfonate (molecular weight 156.01, Aldrich) and 0.1 g dimethoxyphenylacetophenone (molecular weight 256.30, Aldrich) Ionic conductivity measurement results of the solid polymer electrolyte shown in Table 1 are shown in FIG. 2. As can be seen in FIG. 2, the ion conductivity of the solid polymer electrolyte was improved by the addition of titanium dioxide.

Example 7

The solid polymer electrolyte composition of Example 1 was coated on a chromium plate in which a pattern was formed in advance by a bar coating, and then covered with an ITO glass plate coated with WO ₃ in which a pattern was formed in advance, and then fixed, and irradiated with ultraviolet rays of 200 to 400 nm. The solid polymer electrolyte was made into a thin film and then sealed using a silicon binder. Using the obtained solid polymer electrolyte, an electrochromic device as shown in FIG. 3 was manufactured (description of the reference numeral: 1: glass plate or transparent plastic plate, 2: ITO, 3: electrochromic material, 4: solid polymer electrolyte, 5: exterior material) ). The response speed of the electrochromic device manufactured by the above method was measured, and the response speed was shown within several seconds.

As described above, the present invention increased the ion conductivity of the ion conductive thin film by uniformly dispersing titanium dioxide in the polymer matrix of the network structure, the solid polymer thin film produced due to the high refractive index of titanium dioxide exhibits white color Electrolyte for device has the advantage of maximizing color contrast effect in application.

Claims (9)

a) photocuring a mixture comprising polyethylene glycol having an acrylate group or methacrylate group of formula 1, polyethylene glycol having an acrylic or methacrylic reactive group of formula 2 and a low molecular weight polyethylene oxide derivative of formula 3 A polymer matrix obtained by b) a solid polymer electrolyte comprising titanium dioxide dispersed in the polymer matrix and an alkali salt of formula (4). Formula 1 Formula 2 Formula 3 Formula 4 A ⁺ B ^- In Formulas 1 to 3, R ₁ is a hydrogen atom or a straight or branched chain lower alkyl group having 1 to 10 carbon atoms, R ₂ is R ₁ or a compound of Formula 5, n is an integer of 1 to 50 and m and k represent the integer of 2-50. In Formula 4 A ⁺ represents an alkali cation, including lithium and sodium, B ^- is ^{Cl -, Br -, I -} , SCN -, ClO 4 -, CF 3 SO 3 -, N (CF 3 SO 3) ₂ ^-, BF ₄ ^- represents a ^-, PF ₆ ^- or AsF _6. Formula 5 In Formula 5, the definition of R ₁ is as described above. The solid polymer electrolyte of claim 1, wherein the solid polymer electrolyte is white. The solid polymer electrolyte of claim 1, wherein the mixture further comprises an ultraviolet initiator. a) polyethylene glycol having an acrylate group or methacrylate group of formula (1), polyethylene glycol having an acrylic or methacrylic reactive group of formula (2), a low molecular weight polyethylene oxide derivative of formula (3), titanium dioxide and an alkali salt of formula (4) To form a mixture comprising, b) the resulting mixture is applied onto a substrate, c) A method for producing a solid polymer electrolyte according to claim 1, comprising the step of irradiating ultraviolet light to photocuring. Here, the definitions of Chemical Formulas 1 to 4 are the same as in Claim 1. The method of claim 4, wherein the applying of step b) is performed by bar coating, spin coating or silkscreen. An electrochromic device comprising the solid polymer electrolyte according to any one of claims 1 to 3. Polyethylene glycol having an acrylate group or methacrylate group of formula (1), polyethylene glycol having an acrylic or methacryl reactive group of formula (2), polyethylene oxide derivative of low molecular weight (3), titanium dioxide and alkali salt of formula (4) Composition. Here, the definitions of Chemical Formulas 1 to 4 are the same as in Claim 1. 8. The composition of claim 7, wherein said composition further comprises a UV initiator to promote photocuring. 8. The composition of claim 7, wherein the amount of titanium dioxide is used in an amount of 1 to 30% by volume based on the total composition.