KR20180047128A - Polymer Electolyte, an Electrochromic Device Comprising the Same and Method for Preparing thereof - Google Patents

Abstract

The present invention relates to a polymer electrolyte which has high ion conductivity so as to be used as various electrochemical devices, and to an electrochromic device including the same. The polymer electrolyte comprises: a first block including a unit represented by chemical formula 1 by at least 55 wt% of the block; a second block including a unit represented by chemical formula 2 by at least 55 wt% of the block; and a block copolymer forming a micelle structure.

Description

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

The present invention relates to a polymer electrolyte, an electrochromic device including the same, and a method of manufacturing the same.

Electrochromism is a phenomenon in which optical properties such as color and light transmittance of an electrochromic active material are changed by electrochemical oxidation and reduction reactions. The electrochromic device using such a phenomenon is attracting attention in various fields such as a smart window, a smart mirror, or an electronic paper because it can be manufactured with a small area with a small area and low power consumption. Such an electrochromic device is generally configured to include a substrate, a transparent electrode, an electrochromic layer, an electrolyte layer, and an ion storage layer.

On the other hand, the electrolyte layer includes electrolyte ions involved in the electrochromic reaction of the device as being intercalated or deintercalated between the electrochromic layer and the ion storage layer. Therefore, the electrolyte layer contributes greatly to the cycle characteristics and durability of the electrochromic device.

In the case of a liquid electrolyte most widely used as a conventional electrolyte, there is a risk of electrolyte leakage, which may lower the durability of the device. Further, when the device is manufactured in a large area, the liquid electrolyte has a problem that the liquid electrolyte seeps under the device due to gravity. Further, the inorganic solid electrolyte has no problem of the liquid electrolyte as described above, but the ionic conductivity is poor. On the other hand, gel polymer electrolytes are considered to be suitable for realizing light transmission characteristics of electrochromic devices because of their low ionic conductivity and transparency and low haze.

The object of the present invention is to provide a polymer electrolyte which has high ionic conductivity and which can be used as various electrochemical devices.

Another object of the present invention is to provide an electrochromic device having excellent performance and excellent durability over a long period of time by exhibiting a large difference in visible light transmittance and visible light transmittance upon discoloration while having adhesiveness.

The term " block copolymer " may refer to a copolymer in which the different monomers comprise blocks of different polymerized monomers. The meaning that a particular block " comprises " a particular monomer or polymer may mean that the monomer or polymer is included as such, polymerized, derived or derived from a particular monomer or polymer.

The term " micelle structure " is a colloidal dispersion state, which can refer to a solute formed in solution by a certain concentration of solute, and the amphipathic substance is formed in a polar or non-polar solvent by so-called phase separation or self- And the like. The term " amphipathic " may mean that one molecule has both polar and non-polar properties.

The term " polarity " may mean that it partially exhibits electrical properties due to the bias of electrons in the molecule, and " non-polar " refers to a relative concept of polarity that the molecule does not partially exhibit electrical properties, It can mean. In the present specification, " polarity " and " non-polarity " are different from each other in a relative concept, and polarities in which the magnitude of the dipole moment is large can be distinguished from polarity.

The present invention relates to a polymer electrolyte, a method for producing a polymer electrolyte, and an electrochromic device comprising the polymer electrolyte.

In one example of the present application, the present application relates to a polymer electrolyte. The polymer electrolyte according to the present invention comprises a first block comprising at least 55% by weight of a block represented by the formula (1); And a second block comprising a monomer having a crosslinkable functional group and a unit represented by the following formula (2), wherein the unit of formula (2) is at least 55% by weight of the block, and may include a block copolymer forming a micelle structure .

[Chemical Formula 1]

(2)

In Formula (1), A is an alkylene group having 1 to 8 carbon atoms, Q is hydrogen or an alkyl group having 1 to 20 carbon atoms, and B is an alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon or a carboxyl group having 6 to 32 carbon atoms.

The first block of the block copolymer may contain a unit of the formula (1) as a main component. The inclusion of the unit represented by the formula (1) as a main component may mean that at least 55% by weight of the first block of the block copolymer contains the unit of the formula (1), and it may be at least 58 wt%, at least 62 wt% But it is not limited thereto. The upper limit of the unit of the formula (1) in the first block is not particularly limited, and may be, for example, 100% by weight or less.

The alkyl group in A in Formula 1 may have 1 to 8 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 2 carbon atoms, but is not limited thereto.

The first block of the block copolymer is located outside the micelle structure and can support the movement of electrolyte ions due to the pair of non-covalent electrons in the molecules, and the block copolymer containing the first block can be transferred to the polymer electrolyte The polymer electrolyte can exhibit a high ionic conductivity.

In one example, the compound represented by Formula 1 may be any one selected from the group consisting of polyethylene oxide, polypropylene oxide, and polyoxymethylene, or a mixture of two or more thereof. And may be, for example, polyethylene oxide having a number average molecular weight of 500 to 100,000, but is not limited thereto. The term " number average molecular weight " in the present application may mean an analytical value measured by a magnetic resonance apparatus (NMR), and unless otherwise specified, the molecular weight of a polymer may mean the number average molecular weight of the polymer .

In one example, the second block of the block copolymer may comprise a monomer having a crosslinkable functional group. Examples of the crosslinkable functional group include a hydroxyl group, a carboxyl group, an isocyanate group, a glycidyl group, an amine group, an alkoxysilyl group or a vinyl group, and for example, an isocyanate group can be used. The monomer containing an isocyanate group is preferably selected from the group consisting of 2-methacryloyloxyethyl isocyanate, 3-methacryloyloxy-n-propyl isocyanate, 2-methacryloyloxyisopropyl isocyanate, 4- methacryloyloxy- Butyl isocyanate, 2-methacryloyloxy-tert-butyl isocyanate, 2-methacryloyloxybutyl-4-isocyanate, 2- methacryloyloxybutyl-3-isocyanate, 2- methacryloyloxy Methacryloyloxy-n-pentyl isocyanate, 6-methacryloyloxy-n-hexyl isocyanate, 7-methacryloyloxy-n-hexyl isocyanate, 2-methacryloyloxybutyl- Acryloyloxyethyl isocyanate, 4-methacryloyloxyphenyl isocyanate, 4-methacryloyloxyphenyl isocyanate, 2-acryloyloxyethyl (meth) acrylate, Isoshiana N-propyl isocyanate, 2-acryloyloxy isopropyl isocyanate, 4-acryloyloxy-n-butyl isocyanate, 2-acryloyloxy-tert-butyl isocyanate, 2- Acryloyloxybutyl-2-isocyanate, 2-acryloyloxybutyl-1-isocyanate, 5-acryloyloxy, 2-acryloyloxybutyl-3-isocyanate, Acryloyloxy-n-heptyl isocyanate, 2- (isocyanatoethyloxy) ethyl acrylate, 3-acryloyloxy-n-hexyl isocyanate, Bis (methacryloyloxymethyl) ethyl isocyanate, 1,1-bis (methacryloyloxymethyl) ethyl isocyanate, 1,1-bis (Acryloyloxymethyl) methyliso (Acryloyloxymethyl) ethyl isocyanate, 2'-pentenoyl-4-oxyphenyl isocyanate and the like, and examples thereof include 2-methacryloyloxyethyl isocyanate, 4 Methacryloyloxy-n-hexyl isocyanate, 2-acryloyloxyethyl isocyanate, 3-methacryloyloxy-n-butyl isocyanate, (Methacryloyloxymethyl) ethyl isocyanate, 2- (isocyanatoethyloxy) ethyl methacrylate, and 2- (isocyanatoethyloxy) ethyl methacrylate. (Isocyanatoethyloxy) ethyl acrylate, or a mixture of two or more thereof.

By introducing the monomer having a crosslinkable functional group into the second block of the block copolymer, it is possible to provide a crosslinking point to the second block, to crosslink the core part of the block copolymer described later, or to crosslink the oligomer contained in the polymer electrolyte And a crosslinked structure can be formed to increase the structural stability of the polymer electrolyte.

The second block of the block copolymer may contain a unit of the formula (2) as a main component. The inclusion of the unit of the general formula (2) as a main component may mean that at least 55% by weight of the second block of the block copolymer contains the unit of the general formula (2), and it may be at least 58 wt%, at least 62 wt% But it is not limited thereto. The upper limit of the unit of formula (2) in the second block is not particularly limited, and may be 99 wt% or less, 95 wt% or less, 93 wt% or less, or 90 wt% or less.

The alkyl group present in Q in Formula 2 may be an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkyl group may be linear, branched or cyclic. In addition, the alkyl group may be optionally substituted with one or more substituents.

In formula (2), B may be a linear or branched alkyl group having 1 or more carbon atoms, 3 or more carbon atoms, 5 or more carbon atoms, 7 or more carbon atoms, or 9 or more carbon atoms, which may be optionally substituted or unsubstituted. The upper limit of the carbon number of the linear or branched alkyl group is not particularly limited. For example, the alkyl group may be an alkyl group having 32 or less carbon atoms or 30 carbon atoms or less.

In another embodiment, B may be an alicyclic hydrocarbon group, for example, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, 3 to 16 carbon atoms, or 6 to 12 carbon atoms, and examples of the hydrocarbon group include a cyclohexyl group or iso And an alicyclic alkyl group having 3 to 20 carbon atoms, 3 to 16 carbon atoms, or 6 to 12 carbon atoms, such as boronyl group, and the like.

In another embodiment, B in formula (2) may be an aromatic substituent, such as an aryl group or an arylalkyl group. The aryl group in the above may be, for example, an aryl group having 6 to 24 carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms. The alkyl group of the arylalkyl may be, for example, an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Examples of the aryl group or arylalkyl group include, but are not limited to, a phenyl group, a phenylethyl group, a phenylpropyl group or a naphthyl group.

Examples of the substituent which may optionally be substituted in the above alkyl group, aryl group or hydrocarbon group of the above formula (2) include an epoxy group such as a halogen such as chlorine or fluorine, a glycidyl group, an epoxy alkyl group, a glycidoxyalkyl group or an alicyclic epoxy group , An acryloyl group, a methacryloyl group, an isocyanate group, a thiol group, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, but the present invention is not limited thereto.

In one example, in Formula 2, B may be alkyl having 1 to 32 carbon atoms, alkyl having 1 to 30 carbon atoms, 1 to 28 carbon atoms, and 1 to 24 carbon atoms, for example, alkyl having 1 to 16 carbon atoms Lt; / RTI > The compound represented by Formula 2 may be, for example, alkyl (meth) acrylate. In the above, the term "(meth) acrylate" means acrylate or methacrylate. The alkyl (meth) acrylate may be, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, (Meth) acrylate, n-octyl (meth) acrylate, isobornyl (meth) acrylate, isooctyl (meth) acrylate, isononyl However, the present invention is not limited thereto.

The second block may be located at the center of the micelle structure of the block copolymer to form a core having a micelle structure and improve the mechanical properties of the polymer electrolyte of the present application.

In one example, the second block of the block copolymer according to the present application may comprise a unit represented by the following formula (3).

(3)

Wherein Q is hydrogen or an alkyl group having 1 to 20 carbon atoms, X is an alkylene group having 1 to 8 carbon atoms, Y is -OR ₂ or -NR ₃ R ₄ , and R ₂ , R ₃ and R ₄ are each independently An alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon group having 6 to 32 carbon atoms, or a carboxyl group.

The alkyl group present in Q in Formula 3 may be an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkyl group may be linear, branched or cyclic. In addition, the alkyl group may be optionally substituted with one or more substituents.

Examples of the substituent which may optionally be substituted in the above-mentioned alkyl group or hydrocarbon group of the above-mentioned formula (3) include an epoxy group such as a halogen such as chlorine or fluorine, a glycidyl group, an epoxy alkyl group, a glycidoxyalkyl group or an alicyclic epoxy group, A methacryloyl group, an isocyanate group, a thiol group, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, but the present invention is not limited thereto.

In Formula 3, X may be an alkylene group having 1 to 8 carbon atoms, and may be an alkylene group having 1 to 7 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms, but is not limited thereto.

In Formula 3, R ₂ , R ₃ and R ₄ are each independently hydrogen, an alkyl group having 1 to 32 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an alkyl group having 1 to 28 carbon atoms, or an alkyl group having 1 to 24 carbon atoms, Or aromatic hydrocarbons having 6 to 32 carbon atoms, aromatic hydrocarbons having 6 to 28 carbon atoms, aromatic hydrocarbons having 6 to 24 carbon atoms, or carboxyl groups.

In one example of the application, the block copolymer may have a mass ratio of the first block to the second block of from 1: 9 to 9: 1. If it is outside the above range, the block copolymer may not form a micelle structure.

Further, in another example of the present application, the monomer containing the crosslinkable functional group contained in the second block of the block copolymer may crosslink the core portion of the micelle structure. The second methyl of the block copolymer of the present application contains a monomer having a crosslinkable functional group, and the stability of the micelle structure can be secured by crosslinking the core portion of the micelle structure.

In one example, the second block of the block copolymer may form a crosslinked structure with a part of the glycol-based oligomer described below. The fact that the second block and the glycol oligomer form a crosslinked structure can mean that the terminal portion of the glycol oligomer is bonded to the second block of the block copolymer. The " part " of the glycol-based oligomer in which the crosslinked structure is formed may mean that 1 to 30% by weight or 2 to 15% by weight of the glycol based oligomer is bonded to the block copolymer. The long-term durability of the polymer electrolyte can be improved.

In one example, the block copolymer of the present application may have a molecular weight distribution (PDI) of 1.0 to 1.3. The molecular weight distribution (PDI; Mw / Mn) may mean the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn). The molecular weight distribution of the block copolymer may be 1.02 to 1.28, 1.05 to 1.26, and may be, for example, 1.05 to 1.25. When the molecular weight distribution satisfies the above range, the block copolymer of the present application may well form a micelle structure. If the molecular weight distribution is out of the range, the block copolymer may not form a micelle structure.

The block copolymer may have a Number Average Molecular Weight (Mn) in the range of 5,000 to 100,000. The number average molecular weight referred to in the present specification can be measured using GPC (Gel Permeation Chromatograph). The number average molecular weight of the block copolymer can be 6,000 or more, 7,000 or more, 8,000 or more, or 9,000 or more in another example. The number average molecular weight may be in the range of 90,000 or less, 85,000 or less, or 80,000 or less in other examples.

The molecular weight characteristics of the block copolymer can be controlled as described above to provide a polymer electrolyte having excellent physical properties.

In one example, the polymer electrolyte of the present application may comprise 1 to 20 parts by weight of a block copolymer with respect to 100 parts by weight of the whole polymer electrolyte. The block copolymer may include 1 to 18, 1 to 16, and 2 to 14 parts by weight, and preferably 3 to 13 parts by weight, based on 100 parts by weight of the total polymer electrolyte. By controlling the content of the block copolymer in the range of the above range, the difference between the transmittance of the visible light ray during coloring and the transmittance of visible light during decolorization can be kept high and the coloring efficiency can be enhanced, It is possible to exhibit excellent device characteristics.

The method for producing the block copolymer is not particularly limited and can be produced in a usual manner. The block polymer is polymerized by, for example, Living Radical Polymerization, and examples thereof include an organic rare earth metal complex as a polymerization initiator or an organic alkali metal compound as a polymerization initiator to produce an alkali metal or an alkali An anionic polymerization in which an organic alkali metal compound is used as a polymerization initiator and synthesized in the presence of an organoaluminum compound, an atom transfer radical using an atom transfer radical polymerization agent as a polymerization initiator, (ATRP), Atomic Transfer Radical Polymerization (ATRP), Initiators (ICAR), and Carbon Nanotubes (ATRP), which perform polymerization under an organic or inorganic reducing agent that generates electrons using an atom transfer radical polymerization agent as a polymerization initiator for continuous activator regeneration), inorganic reducing agent reversible addition - cleavage Reversible addition using a chain transfer agent-cleavage and the like, a polymerization using a polymerization (RAFT) or an organic tellurium compound by a chain transfer initiator, may be subject to a suitable method among these methods is selected.

In one example of the present application, the polymer electrolyte may comprise a glycolic oligomer. The glycol oligomer may contain a reactive functional group at the terminal thereof, and the number of functional groups is not particularly limited. Examples of the functional group include, but are not limited to, an acrylate group or a diacrylate group.

The glycol-based oligomer may include at least one oligomer selected from the group consisting of a polypropylene glycol oligomer, a polyethylene glycol oligomer, a polyethylene imine oligomer, and an aniline oligomer. The glycol oligomer can form a gel polymer electrolyte through UV irradiation and can realize a polymer structure in which electrolyte ions can be easily moved owing to the pair of non-covalent electrons of oxygen or nitrogen existing in the molecule, and a gel polymer electrolyte Can exhibit good ionic conductivity < RTI ID = 0.0 >

The weight average molecular weight of the glycol oligomer may be 100 to 50,000, or 500 to 20,000, but is not limited thereto.

The content of the glycol oligomer may be 5 to 90 parts by weight, 10 to 90 parts by weight, 20 to 85 parts by weight or 30 to 80 parts by weight based on 100 parts by weight of the total polymer electrolyte. When the content of the glycol oligomer is 5 or less, the polymer electrolyte may not be formed into a film, and sufficient adhesive strength can not be secured.

In one example of the present application, the polymer electrolyte may further include a crosslinkable monomer. When the oligomer or polymer is crosslinked at the time of forming the polymer electrolyte, the crosslinking monomer may form a gel of the polymer electrolyte. The kind of the crosslinkable monomer is not particularly limited. (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, tri (propyleneglycol) di (meth) acrylate, (Meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol tetra (Meth) acrylate, acrylic acid, isobornyl acrylate, acrylonitrile, ethylene glycol (meth) acrylate, ethylhexyl Acrylate, can be used any one of a TMPTA (Trimethylpropane triacrylate), TMPTA with SiO2 50%, ETPTA (Trimethylpropane ethoxylate triacrylate). The content of the crosslinkable monomer may be 0.01 to 30 parts by weight or 0.05 to 10 parts by weight based on 100 parts by weight of the glycol oligomer. When the content of the crosslinkable monomer is less than 0.1, the curing may not be sufficiently performed, and a film-like electrolyte may not be obtained. When the content is more than 30, the transparency of the polymer electrolyte may be lowered.

In one example, the polymer electrolyte according to the present application may further comprise a photoinitiator. The type of the photoinitiator is not particularly limited. For example, acetophenone-based compounds, nonimidazole-based compounds, triazine-based compounds, oxime-based compounds, and the like can be used. The photoinitiator may include 0.01 to 5 parts by weight or 0.01 to 3 parts by weight based on 100 parts by weight of the glycol oligomer. When the content of the photoinitiator is 0.01 or less, the curing may be insufficient or the curing rate may be delayed.

In one example, the metal salt of the polymer electrolyte according to the present application may comprise a lithium compound. The lithium compounds are LiF, LiCl, LiBr, LiI, LiClO 4, LiClO 3, LiAsF 6, LiSbF 6, LiAlO 4, LiAlCl 4, LiNO 3, LiN (CN) 2, LiPF 6, Li (CF 3) 2 PF 4 _{, Li (CF 3) 3 PF} 3, Li (CF 3) 4 PF 2, Li (CF 3) 5 PF, Li (CF 3) 6 P, LiSO 3 CF 3, LiSO 3 C 4 F 9, LiSO 3 ( _{CF 2) 7 CF 3, LiN} (SO 2 CF 3) 2, LiN (SO 2 CaF 2a + 1) (SO 2 C b F 2b + 1) ( stage, a and b are natural numbers), LiOC (CF ₃ ) ₂ CF ₂ CF ₃ , LiCO ₂ CF ₃ , LiCO ₂ CH ₃ , LiSCN, LiB (C ₂ O ₄ ) ₂ , LiBF ₂ (C ₂ O ₄ ) and LiBF ₄ . As described above, the lithium compound may be contained in an amount of 0.1 to 50 parts by weight or 0.5 to 30 parts by weight based on 100 parts by weight of the glycol-based oligomer. When the content of the lithium compound is 25 or less, sufficient ion conductivity may not be secured.

In another example, the polymer electrolyte of the present application may comprise a polar solvent. The polar solvent may be at least one of a carbonate compound, an ether compound and an ester compound.

In one example of the present application, the polar solvent may be a carbonate compound. The carbonate compound may be selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate At least one member selected from the group consisting of ethyl fluoroethyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, and butylenes carbonate. . The carbonate-based compound is used as a plasticizer of the electrolyte. Since the dielectric constant is high, ion conductivity of the gel polymer electrolyte can be increased. The content of the carbonate compound may be 8 to 200 parts by weight or 10 to 150 parts by weight based on 100 parts by weight of the glycol oligomer as described above. When the content of the carbonate compound is 25 or less, ionic conductivity may be lowered.

The polymer electrolyte may include 5 to 25 parts by weight of a lithium compound and 75 to 90 parts by weight of a carbonate compound based on 100 parts by weight of the glycol oligomer. By controlling the composition ratio of the electrolyte of the present application within the above range, a gel polymer electrolyte excellent in adhesion reliability can be formed.

In another example, the present application relates to a method for producing a polymer electrolyte. The method for producing a polymer electrolyte includes a first block including a unit represented by the following formula (1) between a plurality of release films at least 55 wt% of the block; And a second block comprising a monomer having a crosslinkable functional group and a unit represented by the following formula (2), wherein the unit of formula (2) is at least 55% by weight of the block, and the block copolymer forming a micelle structure Coating; And curing the mixture.

[Chemical Formula 1]

(2)

In Formula (1), A is an alkylene group having 1 to 8 carbon atoms, Q is hydrogen or an alkyl group having 1 to 20 carbon atoms, and B is an alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon or a carboxyl group having 6 to 32 carbon atoms.

The mixture may include a glycol-based oligomer, a lithium salt, and a block copolymer forming a micelle structure, and may further include a crosslinking monomer and a photoinitiator.

In one example, the type of the release film is not particularly limited. For example, polyester resins such as polyethylene terephthalate, polybutylene terephthalide, polyethylene naphthalate and polybutylene naphthalate; Polyimide resin; Acrylic resin; Styrenic resins such as polystyrene and acrylonitrile-styrene; Polycarbonate resin; Polylactic acid resin; Polyurethane resin; Polyolefin resins such as polyethylene, polypropylene and ethylene-propylene copolymer; Vinyl resins such as polyvinyl chloride and polyvinylidene chloride; Polyamide resins; Sulfonic resin; Polyether-ether ketone resin; Allylate series resin; Or a release film formed of a mixture of the resins may be used.

In one example, the curing may be performed by irradiating light in a wavelength range of 10 nm to 400 nm with 0.5 to 5 J / cm ² light quantity. Means for Irradiating Light in the Wavelength Range A commonly used apparatus can be used, for example, an Xe lamp, a mercury lamp, or a metal halide lamp.

In another example, the viscosity of the electrolyte composition can be from 10 to 100,000 cps, and from 1,000 to 5,000 cps, based on 25 占 폚. If the viscosity of the electrolyte solution is less than 10 cps, the coating processability may be poor. If the viscosity exceeds 100,000 cps, the film may be difficult to be coated due to mixing and defoaming process.

The present application also relates to an electrochromic device. An exemplary electrochromic device of the present application includes a first electrode; An electrochromic layer; Polymer electrolyte; And a second electrode, wherein the polymer electrolyte includes the block copolymer described above, and the block copolymer may form a micelle structure. The characteristics of the polymer electrolyte are as described above.

The first electrode and the second electrode may be configured to supply electric charge to the electrochromic layer. In one example, the transparent electrode may include at least one of a transparent conductive oxide, a conductive polymer, an Ag nanowire, or a metal mesh. More specifically, it is possible to use a metal oxide such as ITO (indium tin oxide), FTO (fluoro-doped tin oxide), AZO (aluminum doped zinc oxide), GZO (gallium doped zinc oxide), ATO (antimony doped tin oxide), IZO , Niobium-doped Titanium Oxide (NTO), ZnO, Oxide / Metal / Oxide (OMO), and Cadmium Tin Oxide (CTO).

The method for forming the transparent electrode is not particularly limited, and a known method can be used without limitation. For example, a transparent electrode can be provided by forming an electrode material containing transparent conductive oxide particles in a thin film form on a transparent glass substrate through a sputtering process. The transparent electrode may have a thickness of 150 nm or more, 200 nm or more, or 300 nm or more in the range of 1 nm to 1 占 퐉. The upper limit of the thickness of the transparent electrode is not particularly limited, but for the low resistance implementation, the transparent electrode may have a thickness of 800 nm or less, 700 nm or less, or 500 nm or less. In addition, the transparent electrode may have a transmittance of 70% to 90% with respect to visible light in order to sufficiently reflect a change in light transmittance of the electrochromic device.

In the present application, the electrochromic layer and the ion storage layer may include an electrochromic material that performs a redox reaction, and the electrochromic material may exhibit discoloration of coloration and discoloration due to redox reaction. Examples of electrochromic materials that can be used include conductive polymers, organic coloring materials and / or inorganic coloring materials. As the conductive polymer, polypyrrole, polyaniline, polypyridine, polyindole, polycarbazole, and the like can be used. As the organic coloring material, materials such as viologen, anthraquinone, and phenothiazine can be used. It is not.

The inorganic coloring material may include at least one metal oxide selected from oxides of Ti, Nb, Mo, Ta, W, V, Cr, Mn, Co, Ni, Rh and Ir. The electrochromic layer and the ion storage layer may contain an inorganic coloring material that is complementary to each other in the redox reaction. For example, the electrochromic layer may contain at least one of a reducing inorganic coloring material such as TiO ₂ , Nb ₂ O ₅ , MoO ₃ , Ta ₂ O ₅ and WO _{3, which} is an oxide of Ti, Nb, Mo, When the ionic storage layer contains a reducing inorganic coloring material, an oxidizing inorganic coloring material such as V ₂ O ₅ , CrO ₃ , LixCoO ₂ , or LiNiO _x , which is an oxide of V, Cr, Mo, Co, Ni, (Where x is 1 to 3), Rh ₂ O _3, and IrO ₂ .

In the present application, the term " reducing inorganic coloring material " means a material that is colored by a reduction reaction, and the term " oxidative inorganic coloring material " means a material that is colored by an oxidation reaction.

In another example, the electrochromic layer may have a transmittance of 10% to 30% with respect to visible light in coloring and a transmittance of 55% to 75% with respect to visible light in decolorizing. Further, the electrochromic layer may have a thickness of 350 nm or less, 250 nm or less, 150 nm or less, or 120 nm or less in the range of 50 nm to 400 nm. When the thickness is less than 50 nm, the reaction for discoloration is difficult to occur sufficiently. When the thickness exceeds 150 nm, it is impossible to provide a thin film electrochromic device and the transmittance of the device may be reduced.

The ion storage layer may have a transmittance of 5% to 40% with respect to visible light in coloring and a transmittance of 45% to 80% with respect to visible light in decolorizing. Further, the electrochromic layer may have a thickness within a range of 10 nm to 400 nm of 350 nm or less, 250 nm or less, 150 nm or less, or 120 nm or less. If the thickness is less than 10 nm, the reaction for discoloration is difficult to occur sufficiently. If the thickness is more than 150 nm, a thin film electrochromic device can not be provided, and the transmittance of the device may be reduced.

According to the present application, a polymer electrolyte comprising a block copolymer of a micelle structure and a crosslinked polymer matrix exhibits excellent ionic conductivity. In addition, the polymer electrolyte of the present application can improve the optical characteristics and bistability of the electrochromic device when applied to an electrochromic device, and can improve long-term durability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a block copolymer of the present application. FIG.
Fig. 2 shows the measurement results for confirming the micelle structure of the block copolymer synthesized in Production Example 1. Fig.
Fig. 3 is a measurement result for confirming the micelle structure of the block copolymer synthesized in Production Example 2. Fig.
4 is a graph showing the characteristics of the electrochromic device depending on the kind of the polymer electrolyte.
5 is a result of the durability test when the block copolymer according to the present application is added.

Hereinafter, the present application will be described in detail by way of examples, but the scope of the polymer electrolyte is not limited by the following embodiments.

The physical properties of the present examples and comparative examples were evaluated in the following manner.

Manufacturing example  1. Preparation of block copolymer (A1)

To prepare an initiator for Atom Transfer Radical Polymerization (ATRP), 3 equivalents of triethylamine (TEA) and 2 equivalents of 2-bromo isobutyryl per mole equivalent of the terminal hydroxy (mPEG-OH) Add 2 equivalents of 2-bromo isobutyryl bromide and react. In order to remove impurities, the reaction product was dissolved in a diethyl ether solvent to recover the precipitate, which was repeated twice and then dried.

The prepared initiator has bromine at the end of the polyethylene glycol (PEG) polymer. The resulting initiator is dissolved in ethanol as a reaction solvent, and 43 weight parts of methyl methacrylate and 4.75 weight parts of hydroxypropyl methacrylate are added. The flask is sealed with a rubber membrane, and nitrogen is bubbled through the mixture for 30 minutes while stirring at room temperature to remove dissolved oxygen. After that, the flask was immersed in an oil bath at 60 ° C, and the catalyst solution and the catalyst reducing agent were added thereto, and the reaction was carried out for 24 hours. As the catalyst of ATRP, 100 ppm of copper bromide (CuBr 2) and 2 equivalents of tris (2-pyridylmethyl) amine (TPMA) relative to copper were dissolved in acetonitrile. As the catalyst reducing agent, 6 equivalents (relative to Cu) of 2,2'-azobis (2.4-dimethylvaleronitrile) (V-65) was used.

The resulting block polymer is dissolved in ethyl acetate. This was immersed in an oil bath set at 60 DEG C under an oxygen pressure, and then 1 equivalent of 2-isocyanatoethyl acrylate (AOI, 2-Isocyanatoethyl acrylate) was added to the hydroxy functional group of the hydroxypropyl methacrylate, 0.1 equivalent of tin dyer lyrate (DBTDL) was added and stirred for 4 hours to introduce urethane reaction between the hydroxy functional group and the isocyanate group of 2-isocyanatoethyl acrylate to introduce an acryloyl group. After the reaction is completed, precipitate in cold isopropyl alcohol: hexane = 1: 1 mixed solution.

Manufacturing example  2 to 4. Preparation of block copolymers (A2, B1, B2)

A block copolymer was prepared in the same manner as in Preparation Example 1, except that the raw materials used in the polymerization of the first block and the second block were adjusted in the same ratios as in Table 1

Molecular weight (Mw) The dispersion degree (PDI) PEO: PMMA: AOI: DMAEMA (mass ratio) Production Example 1 (A1) 12,000 1.10 80: 18: 2: 0 Production Example 2 (A2) 11,000 1.21 50: 33: 2: 15 Production Example 3 (B1) 17,000 1.16 50: 42.5: 2.5: 5 Production Example 4 (B2) 15,000 1.11 50: 45: 0: 5

PEO: Polyethylene oxide

PMMA: Poly methyl methacrylate (PMMA)

AOI: Isocyanatoethyl acrylate (2-isocyanatoethyl acrylate)

DMAEMA: N, N-Dimethylaminoethyl methacrylate (N, N-dimethylaminoethyl methacrylate)

1. Evaluation of copolymer properties

(1) Confirmation of copolymer formation

0.3 g of the copolymer (A1, A2) prepared in the above Production Example was dissolved in 10 g of a polycarbonate solvent, and a particle size analysis (DLS) measurement was performed after 24 hours. The size of the micelles of the polyethylene oxide-polymethyl methacrylate block copolymer is known and has a size of about 300 to 400 nm.

The results of the measurement of Production Example 1 (A1) are shown in FIG. 2, and 48% of the total block copolymers have a micellar structure because there are about 48% of the particles having a size of 371.5 d · nm in the solution.

The results of the measurement of Production Example 2 (A2) are shown in FIG. 3, and 42% of particles having a size of 355.5 d · nm exist in the solution. Therefore, it can be confirmed that 42% of all the block copolymers have a micelle structure.

(2) Molecular weight and composition ratio

The block ratios and molecular weights of the prepared block polymers were evaluated by the following methods and shown in Table 1 above.

Specifically, the solid solution was solidified through purification of the polymer solution completely removed from the catalyst, and the block ratio of the block polymer was confirmed through nuclear magnetic resonance ( ¹ H NMR) analysis. Purification of the polymer solution was carried out by passing through an alumina column to remove the copper complex catalyst, and then added to an excessive amount of diethyl ether while stirring to remove the residual monomer, thereby solidifying the polymer. The solidified polymer was dried in a vacuum oven for 24 hours. The block polymer purified by the above method was dissolved in a solvent of CDCl ₃ and measured by nuclear magnetic resonance ( ¹ H NMR) analysis equipment. As a result of the analysis, 1H peak derived from CH ₂ ═C (CH ₃ ) - at the acrylate monomer double bond end was not confirmed, and it was confirmed that unreacted monomer was not present. Also, the 3H peak derived from -OCH ₃ at the end of the ethylene glycol block was confirmed to be around 3.2 ppm, and the ratio and the molecular weight of each polymer block were calculated based on this. A 450 H peak (4H X repeating units: 113) derived from -CH ₂ CH ₂ O- of ethylene glycol formed of a polymer appears in the range of 3.6 to 3.8 ppm, and a peak near the main chain of methyl methacrylate formed of the polymer Since the 3H peak derived from CH3 appears in the range of 3.5 to 3.6 ppm, the content of each constituent monomer is calculated as a mass fraction by calculating the area ratio thereof. The 2H peaks derived from -OCH ₂ - adjacent to dimethylaminoethyl methacrylate formed of a polymer and 2-isocyanate methyl acrylate COO- appear in the range of 4.0 to 4.2 ppm and 3.9 to 4.0 ppm, respectively, The monomer content was calculated as the mass fraction.

Example  One

Preparation of coating liquid

A mixed solution of 1.25 g of the block copolymer (A1) prepared in Preparation Example 1, 10 g of the lithium salt and the solvent, 3.75 g of the glycol oligomer, 0.3 g of the crosslinkable monomer and 0.03 g of the photoinitiator was mixed at 600 rpm For 3 hours or more. Afterwards, the lid of the container is opened slightly for 3 hours to remove the bubbles formed in the solution. All processes proceed in a yellow room where UV is blocked.

Preparation of Polymer Electrolyte

A predetermined amount of the coating liquid is applied between the release films, and the film is covered. This is followed by baker applicator (Bakers applicator) to make uniform thickness. It is placed in a UV curing unit and cured for 1 minute to obtain a polymer electrolyte in the form of a freestanding film. The permeability, turbidity, and ionic conductivity of the resulting polymer electrolyte were measured.

Manufacture of electrochromic devices

After the electrochromic layers such as WO ₃ and PB were prepared on the ITO film, a polymer electrolyte film cured to a uniform thickness on the release film was laminated on the electrochromic layer, and the electrochromic layers were sandwiched on both sides. The performance of the device according to the applied voltage was measured.

Example  2 and Comparative Example  1 to 2

Polymer electrolytes were prepared in the same manner as in Example 1, except that components and ratios were adjusted as shown in Table 2 below.

Lithium salt and solvent (g) The block copolymer (g) The glycol-based oligomer (g) The crosslinkable monomer (g) The photoinitiator (g) Example 1 10 1.25 (A1) 3.75 0.3 0.03 Example 2 10 1.67 (A2) 3.33 0.3 0.03 Comparative Example 1 10 0 10 0.3 0.03 Comparative Example 2 10 1.25 (B1) 3.75 0.5 0.03 Comparative Example 3 10 0.83 (B2) 4.17 0.3 0.03

Lithium salt and solvent: LiClO ₄ dissolved in propylene carbonate (concentration of 1M, 1.66 g of lithium salt dissolved in 8.34 g of propylene carbonate solvent)

Glycol-based oligomers: oligomers based on PPG (polypropylene glycol)

Crosslinkable monomers: AA (acrylic acid)

Photoinitiator: Irgacure 819 (manufactured by Ciba)

2. Characterization of electrochromic devices

(1) Ion conductivity

To measure the impedance, a gel polymer electrolyte sample having a constant width (A) and a thickness (t) was prepared. A stainless steel (SUS) substrate having excellent electron conductivity was brought into contact with both sides of a plate-shaped sample as an ion blocking electrode, and an alternating voltage was applied through the electrodes on both sides of the sample. At this time, the applied condition was amplitude and the number of measured chopped waves was set in the range of 0.1 Hz to 10 Hz. The resistance of the bulk electrolyte was obtained from the intersection (Rb) where the semicircle or straight line of the measured impedance trajectory meets the real axis and the ion conductivity was obtained from the sample width (A) and thickness (t) as shown in the following equation.

(2) Transmittance and turbidity

The transmittance of the polymer electrolyte film was measured based on the 550 nm wavelength of the UV-Vis spectrum. The haze is Td / Tt, the smaller the value, the more transparent the film. This was done using a haze meter.

(3) Color Transmittance and Decolorization Transmittance

The application of a voltage of -2 V and +2 V to the electrochromic device for 100 seconds was made one cycle. The transmittance at the time of coloration / decolorization was measured based on the wavelength of 550 nm of the UV-Vis spectrum when the voltage was applied for 90 seconds or more in the colored or discolored state.

(4) Bistable  Test( Bistability  Test)

The voltage was applied to the electrochromic device to make it in a decolorized state. Then, the applied voltage was cut off and the change of the transmittance with time was measured.

(5) Durability evaluation

A voltage was applied to the electrochromic device using a potentiostat at -2 V and +2 V for 50 seconds. The cycle was repeated to measure the amount of charge.

The results of the physical properties evaluation for each of the examples and comparative examples are shown in Tables 3, 4 and 5 below.

Permeability (%) Turbidity (%) Ion conductivity (S / cm) Attachment reliability Example 1 95.3 1.2 1.39 x 10 ^-3 ○ Example 2 95.0 1.6 1.42 x 10 ^-3 ○ Comparative Example 1 93.8 1.1 3.48 × 10 ^-4 ○ Comparative Example 2 93.4 0.9 3.13 × 10 ^-4 ○ Comparative Example 3 93.0 1.3 7.46 × 10 ^-4 ○

Color Transmission (%) Decolorization Transmittance (%) ΔT Example 1 33 79 46 Example 2 23 86 63 Comparative Example 1 33 68 35 Comparative Example 2 30 73 43 Comparative Example 3 32 72 40

ΔT = visible light transmittance during decolorization - visible light transmittance during coloring

As can be seen from Tables 3 and 4, transparency was secured due to high transparency and low haze in all of Examples and Comparative Examples. However, when the polymer electrolytes of Examples 1 and 2 were used, ion conductivity was high and visible light transmittance And the visible light transmittance difference is large in coloring, it can exhibit excellent performance when used as an electrochromic device. Also, as can be seen from FIG. 4, an electrochromic device having excellent bistability can be provided. As can be seen from FIG. 5, an electrochromic device having excellent long-term durability can be provided.

Claims (14)

A first block comprising at least 55% by weight of a block represented by the formula (1); And a second block comprising a monomer having a crosslinkable functional group and a unit represented by the following formula (2), wherein the unit represented by the formula (2) is at least 55% by weight of the block, and the polymer electrolyte comprising a block copolymer forming a micelle structure :
[Chemical Formula 1]

(2)

In Formula (1), A is an alkylene group having 1 to 8 carbon atoms, Q is hydrogen or an alkyl group having 1 to 20 carbon atoms, and B is an alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon or a carboxyl group having 6 to 32 carbon atoms.
The polymer electrolyte of claim 1, wherein the second block of the block copolymer further comprises a unit represented by the following formula (3):
(3)

Wherein Q is hydrogen or an alkyl group having 1 to 20 carbon atoms, X is an alkylene group having 1 to 8 carbon atoms, Y is -OR ₂ or -NR ₃ R ₄ , and R ₂ , R ₃ and R ₄ are each independently An alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon group having 6 to 32 carbon atoms, or a carboxyl group, and m is an integer of 1 to 20.
The polymer electrolyte of claim 1, wherein the mass ratio of the first block to the second block is 1: 9 to 9: 1.
The polymer electrolyte according to claim 1, wherein the core of the micelle structure forms a crosslinked structure.
The polymer electrolyte according to claim 1, wherein the block copolymer has a molecular weight distribution (PDI) of 1.0 to 1.3.
The polymer electrolyte according to claim 1, wherein the block copolymer is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total polymer electrolyte.
The polymer electrolyte according to claim 1, further comprising a glycol-based oligomer.
The polymer electrolyte according to claim 7, wherein a part of the glycol oligomer forms a crosslinked structure with the second block of the block copolymer.
According to claim 1, LiF, LiCl, LiBr, LiI , LiClO 4, LiClO 3, LiAsF 6, LiSbF 6, LiAlO 4, LiAlCl 4, LiNO 3, LiN (CN) 2, LiPF 6, Li (CF 3) 2 PF ₄ , Li (CF ₃ ) ₃ PF ₃ , Li (CF ₃ ) ₄ PF ₂ , Li (CF ₃ ) ₅ PF, Li (CF ₃ ) ₆ P, LiSO ₃ CF ₃ , LiSO ₃ C ₄ F ₉ , LiSO ₃ (CF ₂ ) ₇ CF ₃ , LiN (SO ₂ CF ₃ ) ₂ and LiN (SO ₂ CaF _{2a + 1} ) (SO ₂ C _b F _{2b + 1} ) _{CF 3) 2 CF 2 CF 3} , LiCO 2 CF 3, LiCO 2 CH 3, the _{LiSCN, LiB (C 2 O 4} ) 2, LiBF 2 (C 2 O 4) , and LiBF ₄ at least one compound selected from the group consisting of Further comprising a polymer electrolyte.
The polymer electrolyte according to claim 1, further comprising a polar solvent.
11. The polymer electrolyte according to claim 10, wherein the polar solvent is at least one of a carbonate compound, an ether compound and an ester compound.
The polymer electrolyte according to claim 1, further comprising a crosslinkable monomer.
A first block including a unit represented by the following formula (1) in an amount of not less than 55% by weight of the block among a plurality of release films; And a second block comprising a monomer having a crosslinkable functional group and a unit represented by the following formula (2), wherein the unit of formula (2) is at least 55% by weight of the block, and the block copolymer forming a micelle structure Coating; And
And curing the mixture. A method for producing a polymer electrolyte comprising:
[Chemical Formula 1]

(2)

In Formula (1), A is an alkylene group having 1 to 8 carbon atoms, Q is hydrogen or an alkyl group having 1 to 20 carbon atoms, and B is an alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon or a carboxyl group having 6 to 32 carbon atoms.
A first electrode; An electrochromic layer; The polymer electrolyte of claim 1; Ion storage layer; And a second electrode.

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