KR102071912B1 - Polymer Electolyte, an Electrochromic Device Comprising the Same and Method for Preparing thereof - Google Patents

Abstract

The present application relates to a polymer electrolyte and an electrochromic device including the same. According to the present application, the polymer electrolyte may include a crosslinked polymer matrix and a block copolymer, thereby improving ion conductivity, transmittance and bistable stability when coloring and decolorizing in visible light.

Description

Polymer electrolyte and electrochromic device comprising the same {Polymer Electolyte, an Electrochromic Device Comprising the Same and Method for Preparing Flowers}

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

Electrochromism refers to a phenomenon in which optical properties such as color or light transmittance of an electrochromic active material change depending on an electrochemical oxidation and reduction reaction. Electrochromic devices using such a phenomenon can be manufactured in a large area of the device at a low cost, and has a low power consumption, attracting attention in various fields such as smart windows, smart mirrors or electronic paper. 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.

Meanwhile, the electrolyte layer includes electrolyte ions involved in the electrochromic reaction of the device while being inserted or detached 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 the liquid electrolyte most widely used as a conventional electrolyte, there is a risk of leakage of the electrolyte may reduce the durability of the device. In addition, the liquid electrolyte has a problem in that when the device is manufactured in a large area, the liquid electrolyte is concentrated under the device by gravity. In addition, the inorganic solid electrolyte is not a problem of the liquid electrolyte as described above, but the ion conductivity is poor. On the other hand, the gel polymer electrolyte has excellent ion conductivity and permeability, but has a low haze, and thus, the gel polymer electrolyte is considered to be suitable for realizing light transmission characteristics of the electrochromic device.

An object of the present application is to provide a polymer electrolyte that can be used in a variety of electrochemical devices with high ion conductivity.

Another object of the present application is to provide an electrochromic device having adhesiveness and excellent performance by having a large difference in visible light transmittance when discoloring and visible light transmittance when discoloring.

The term "block copolymer" may refer to a copolymer comprising blocks of different polymerized monomers. The meaning of “including” a specific monomer or polymer in a specific block may mean that the monomer or polymer is included as it is, or is polymerized, derived or derived from the specific monomer or polymer.

The term “micel structure” is a colloidal dispersion state, which may refer to an assembly formed by reaching a certain concentration of solute in a solution, and an amphiphilic substance is formed by so-called phase separation or self-assembly in a polar or nonpolar solvent. It can mean a structure that is. The term "amphiphilic" may mean that one molecule has both polar and nonpolar properties.

The term "polarity" may mean that the electrical properties partially due to the bias of the electrons in the molecule, "non-polarity" is a relative concept of the polarity is that the molecule does not exhibit any electrical properties, or even weaker than the polarity. Can mean. In the present specification, "polar" and "non-polar" are relative concepts, and different molecules may be distinguished from each other by a large polarity and a small polarity.

The present application relates to a polymer electrolyte, a method for producing a polymer electrolyte, and an electrochromic device including the same.

In one example of the present application, the present application relates to a polymer electrolyte. The polymer electrolyte according to the present application may include a first block including 55 wt% or more of a unit represented by Formula 1 below; And a monomer having a crosslinkable functional group and a unit represented by the following Chemical Formula 2, wherein the unit of Chemical Formula 2 includes a second block having 55% by weight or more of the block, and may include a block copolymer forming a micelle structure. .

[Formula 1]

[Formula 2]

In Formula 1, A is an alkylene group having 1 to 8 carbon atoms, Q in Formula 2 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 having 6 to 32 carbon atoms or a carboxyl group.

The first block of the block copolymer may include a unit of Formula 1 as a main component. The inclusion of the unit of formula 1 as a main component may mean that at least 55% by weight of the first block of the block copolymer includes the unit of formula 1, and may be at least 58% by weight, at least 62% by weight, or for example 65 wt% or more, but is not limited thereto. In addition, the upper limit of the unit of Formula 1 of the first block is not particularly limited, and may be, for example, 100 wt% or less.

The alkyl group present in A in Formula 1 may be 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 of the micellar structure, and may help to transfer electrolyte ions due to the unshared electron pairs of oxygen present in the molecule, and the block copolymer including the first block may be added to the polymer electrolyte. By use, the polymer electrolyte can exhibit 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. For example, but may be a polyethylene oxide having a number average molecular weight of 500 to 100,000, but is not limited thereto. In the present application, the term "number average molecular weight" may mean an analytical value measured by a magnetic resonance apparatus (NMR), and unless otherwise specified, the molecular weight of any polymer may mean the number average molecular weight of the polymer. .

In one example, the second block of the block copolymer may include a monomer having a crosslinkable functional group. As the crosslinkable functional group, a hydroxy group, a carboxyl group, an isocyanate group, a glycidyl group, an amine group, an alkoxy silyl group or a vinyl group can be exemplified. For example, an isocyanate group can be used. The monomer containing an isocyanate group is 2-methacryloyloxyethyl isocyanate, 3-methacryloyloxy-n-propyl isocyanate, 2-methacryloyloxyisopropyl isocyanate, 4-methacryloyloxy-n -Butyl isocyanate, 2-methacryloyloxy-tert-butyl isocyanate, 2-methacryloyloxybutyl-4-isocyanate, 2-methacryloyloxybutyl-3-isocyanate, 2-methacryloyloxy Butyl-2-isocyanate, 2-methacryloyloxybutyl-1-isocyanate, 5-methacryloyloxy-n-pentyl isocyanate, 6-methacryloyloxy-n-hexyl isocyanate, 7-methacrylo Iloxy-n-heptyl isocyanate, 2- (isocyanatoethyloxy) ethyl methacrylate, 3-methacryloyloxyphenyl isocyanate, 4-methacryloyloxyphenyl isocyanate, 2-acryloyloxyethyl Isociane , 3-acryloyloxy-n-propyl isocyanate, 2-acryloyloxyisopropyl isocyanate, 4-acryloyloxy-n-butyl isocyanate, 2-acryloyloxy-tert-butyl isocyanate, 2-acrylic Loyloxy butyl-4-isocyanate, 2-acryloyloxybutyl-3-isocyanate, 2-acryloyloxybutyl-2-isocyanate, 2-acryloyloxybutyl-1-isocyanate, 5-acryloyl jade Cy-n-pentyl isocyanate, 6-acryloyloxy-n-hexyl isocyanate, 7-acryloyloxy-n-heptyl isocyanate, 2- (isocyanatoethyloxy) ethyl acrylate, 3-acryloyl Oxyphenyl isocyanate, 4-acryloyloxyphenyl isocyanate, 1,1-bis (methacryloyloxymethyl) methyl isocyanate, 1,1-bis (methacryloyloxy methyl) ethyl isocyanate, 1,1-bis (Acryloyloxymethyl) methyl iso Anate, 1,1-bis (acryloyloxymethyl) ethyl isocyanate, 2'-pentenoyl-4-oxyphenyl isocyanate, and the like, for example, 2-methacryloyloxyethyl isocyanate, 4 -Methacryloyloxy-n-butyl isocyanate, 5-methacryloyloxy-n-pentyl isocyanate, 6-methacryloyloxy-n-hexyl isocyanate, 2-acryloyloxyethyl isocyanate, 3-metha Chryloyloxyphenyl isocyanate, 4-methacryloyloxyphenyl isocyanate, 1,1-bis (methacryloyloxymethyl) ethyl isocyanate, 2- (isocyanatoethyloxy) ethyl methacrylate and 2- It may be any one selected from the group consisting of (isocyanatoethyloxy) ethyl acrylate or a mixture of two or more thereof.

By introducing the monomer having the crosslinkable functional group into the second block of the block copolymer, a crosslinking point can be provided to the second block, and the oligomer contained in the polymer electrolyte or crosslinked the core portion of the block copolymer described later. Forming a crosslinked structure with can increase the structural stability of the polymer electrolyte.

In addition, the second block of the block copolymer may include a unit of Formula 2 as a main component. The inclusion of the unit of formula (2) as a main component may mean that at least 55% by weight of the second block of the block copolymer includes the unit of formula (2), and may be at least 58% by weight, at least 62% by weight, or for example 65 wt% or more, but is not limited thereto. In addition, the upper limit of the unit of Formula 2 of the second block is not particularly limited, and may be 99 wt% or less, 95 wt% or less, 93 wt% or less, or, for example, 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 straight or branched chain 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 or less carbon atoms.

In Formula 2, B may be, in another example, 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 such hydrocarbon group include cyclohexyl group or iso And alicyclic alkyl groups having 3 to 20 carbon atoms, 3 to 16 carbon atoms, or 6 to 12 carbon atoms, and the like, may be exemplified.

In Formula 2, B may be, in another example, an aromatic substituent, for example, an aryl group or an arylalkyl group. The aryl group may be, for example, an aryl group having 6 to 24 carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms. In addition, 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, phenyl group, phenylethyl group, phenylpropyl group or naphthyl group.

Examples of the substituent that may be optionally substituted with an alkyl group, an aryl group, or a hydrocarbon group represented by the formula (2) include an epoxy group such as halogen, glycidyl group, epoxyalkyl group, glycidoxyalkyl group or alicyclic epoxy group such as chlorine or fluorine. , Acryloyl group, methacryloyl group, isocyanate group, thiol group, alkyl group, alkenyl group, alkynyl group or aryl group may be exemplified, but is not limited thereto.

In one example, B in Formula 2 may be alkyl having 1 to 32 carbon atoms, alkyl having 1 to 30 carbon atoms, 1 to 28 carbon atoms, alkyl having 1 to 24 carbon atoms, for example, alkyl having 1 to 16 carbon atoms. Can be. The compound represented by Formula 2 may be, for example, alkyl (meth) acrylate. The term "(meth) acrylate" means acrylate or methacrylate above. The said alkyl (meth) acrylate is methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acryl, for example. Late, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth ) Acrylate, n-octyl (meth) acrylate, isobornyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate or lauryl (meth) acrylate and the like can be exemplified. 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 of the micelle structure, and may improve 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 include a unit represented by the following formula (3).

[Formula 3]

In Formula 3, 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 And hydrogen, an alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon or carboxyl group having 6 to 32 carbon atoms.

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 that may be optionally substituted with an alkyl group or a hydrocarbon group of Formula 3 may include epoxy groups such as halogen, glycidyl group, epoxyalkyl group, glycidoxyalkyl group or alicyclic epoxy group such as chlorine or fluorine, and acryl. Diary, methacryloyl group, isocyanate group, thiol group, alkyl group, alkenyl group, alkynyl group or aryl group may be exemplified, but is not limited thereto.

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

R ₂ , R ₃ , and R ₄ in Formula 3 may each independently be 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 an aromatic hydrocarbon having 6 to 32 carbon atoms, an aromatic hydrocarbon having 6 to 28 carbon atoms, an aromatic hydrocarbon having 6 to 24 carbon atoms, or a carboxyl group.

In one example of the present application, the block copolymer may have a mass ratio of 1: 9 to 9: 1 of the first block and the second block. Outside the above range, the block copolymer may not form a micelle structure.

In another example of the present application, the monomer including a crosslinkable functional group included in the second block of the block copolymer may crosslink the core portion of the micelle structure. The second block of the block copolymer of the present application includes a monomer having a crosslinkable functional group, and the stability of the micelle structure can be ensured 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 to be described later. When the second block and the glycol-based oligomer form a crosslinked structure, it may mean that the terminal portion of the glycol-based oligomer is bonded to the second block of the block copolymer. In addition, "part of" the glycol-based oligomer to form a crosslinked structure may mean that 1 to 30% by weight or 2 to 15% by weight based on the total glycol-based oligomer is bonded to the block copolymer, the above range If it satisfies 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 a ratio (Mw / Mn) of weight average molecular weight (Mw) and 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, for example, may be 1.05 to 1.25. In the block copolymer of the present application, when the molecular weight distribution satisfies the range, the block copolymer may form a micelle structure well, and when the block copolymer 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) within a range of 5,000 to 100,000. The number average molecular weight mentioned in this specification can be measured using GPC (Gel Permeation Chromatograph). The number average molecular weight of the block copolymer may be at least 6,000, at least 7,000, at least 8,000, or at least 9,000 in another example. The number average molecular weight may be 90,000 or less, 85,000 or less, or 80,000 or less in another example.

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

In one example, the polymer electrolyte of the present application may include 1 to 20 parts by weight of the block copolymer based on 100 parts by weight of the total polymer electrolyte. The block copolymer may include 1 to 18, 1 to 16, 2 to 14 parts by weight, preferably 3 to 13 parts by weight based on 100 parts by weight of the total polymer electrolyte. In the polymer electrolyte of the present application, by controlling the content of the block copolymer in the above range, it is possible to maintain a high difference in the transmittance of visible light at the time of coloration and the transmittance of visible light at the time of decolorization, and to increase the coloration efficiency, thereby making the polymer electrolyte electrochromic device. When used as it can exhibit excellent device characteristics.

The method for producing the block copolymer is not particularly limited and can be prepared in a conventional manner. The block polymer may be polymerized by, for example, living radical polymerization, for example, an alkali metal or an alkali using an organic rare earth metal complex as a polymerization initiator or an organic alkali metal compound as a polymerization initiator. Anion polymerization synthesized in the presence of an inorganic acid salt such as an earth metal salt, an anion polymerization synthesized in the presence of an organoaluminum compound using an organoalkalimetallic compound as a polymerization initiator, an atom transfer radical using an atom transfer radical polymerizer as a polymerization control agent Activators Regenerated by Electron Transfer (ARRP) Atomic Radical Polymerization (ATRP), ICAR (Initiators), which uses an atomic transfer radical polymerizer as a polymerization control agent and performs polymerization under an organic or inorganic reducing agent that generates electrons. for continuous activator regeneration) 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 include a glycol-based oligomer. The glycol-based oligomer may include a reaction functional group at its terminal, 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 oligomer may include at least one oligomer of a polypropylene glycol oligomer, a polyethylene glycol oligomer, a polyethylene imine oligomer, and an aniline oligomer. The glycol-based oligomer can form a gel polymer electrolyte through UV irradiation, and can implement a polymer structure that is easy to move the electrolyte ions due to the non-covalent electron pair of oxygen or nitrogen present in the molecule, gel polymer electrolyte comprising the same Can exhibit excellent ionic conductivity

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

The content of the glycol-based 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-based oligomer is 5 or less, the polymer electrolyte may not be formed into a film, and may not exhibit sufficient adhesive force, and thus may exhibit low performance due to interfacial resistance during device fabrication.

In one example of the present application, the polymer electrolyte may further include a crosslinkable monomer. The crosslinkable monomer may crosslink an oligomer or a polymer when the polymer electrolyte is formed, such that the polymer electrolyte may form a gel. The kind of the crosslinkable monomer is not particularly limited. For example, ethylene glycol di (meth) acrylate, poly (ethylene glycol) di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tri (propylene glycol) di (meth) acrylate, Tris (2- (meth) acryloethyl) isocyanurate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) Acrylate, acrylic acid, isobornyl acrylate, acrylonitrile, ethylene glycol (meth) acrylate, ethylhexyl (meth) acrylate or methyl (meth) arc Acrylate, it 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 relative to 100 parts by weight of the glycol-based oligomer. When the content of the crosslinkable monomer is 0.1 or less, curing may not be sufficiently performed, an electrolyte in the form of a film may not be obtained, and when 30 or more, transparency of the polymer electrolyte may be lowered.

In one example, the polymer electrolyte according to the present application may further include a photoinitiator. The kind of the photoinitiator is not particularly limited. For example, acetophenone compounds, biimidazole compounds, triazine compounds, oxime 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-based oligomer. When the content of the photoinitiator is 0.01 or less, curing may not be sufficiently performed or the curing speed may be delayed.

In one example, the metal salt of the polymer electrolyte according to the present application may include a lithium compound. The lithium compound is 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} ) (where 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 one or more selected from the group consisting of LiBF ₄ . As described above, the lithium compound may be included 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 ionic conductivity may not be secured.

In another example, the polymer electrolyte of the present application may include 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-based compound. The carbonate-based compound is dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate ), At least one selected from the group consisting of ethyl fluoroethyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, and butylene carbonate. Can be. The carbonate-based compound is used as a plasticizer of the electrolyte, and can increase the ionic conductivity of the gel polymer electrolyte because of its high dielectric constant. As described above, the content of the carbonate-based compound may be included in an amount of 8 to 200 parts by weight or 10 to 150 parts by weight with respect to 100 parts by weight of the glycol-based oligomer. When the content of the carbonate compound is 25 or less, ionic conductivity may decrease.

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

In another example, the present application is directed to a method of making a polymer electrolyte. The manufacturing method of the polymer electrolyte may include a first block including 55 wt% or more of a unit represented by Chemical Formula 1 between a plurality of release films; And a monomer having a crosslinkable functional group and a unit represented by the following Chemical Formula 2, wherein the unit of Chemical Formula 2 includes a second block having 55% by weight or more of the block and comprises a block copolymer forming a micelle structure. Coating; And curing the mixture.

[Formula 1]

[Formula 2]

In Formula 1, A is an alkylene group having 1 to 8 carbon atoms, Q in Formula 2 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 having 6 to 32 carbon atoms or a carboxyl group.

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

In one example, the kind of the release film is not particularly limited. For example, Polyester resins, such as a polyethylene terephthalate, a polybutylene terephthalate, a polyethylene naphthalate, a polybutylene naphthalate; Polyimide resins; Acrylic resins; Styrene resins such as polystyrene and acrylonitrile-styrene; Polycarbonate resins; Polylactic acid resins; Polyurethane resins; Polyolefin resins such as polyethylene, polypropylene, ethylene-propylene copolymers; Vinyl resins such as polyvinyl chloride and polyvinylidene chloride; Polyamide resins; Sulfone resins; Polyether ether ketone resins; Allyl resins; Alternatively, a release film formed of a mixture of the above resins may be used.

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

In another example, the viscosity of the electrolyte composition may be 10 to 100,000 cps, and 1,000 to 5,000 cps based on 25 ° C. When the viscosity of the electrolyte solution is less than 10 cps coating processability may be lowered, and when the viscosity of the electrolyte solution exceeds 100,000 cps it may be difficult to coat the film form due to poor mixing and defoaming process.

The present application also relates to an electrochromic device. Exemplary electrochromic device of the present application is a first electrode; Electrochromic layer; Polymer electrolytes; And an electrochromic device comprising a second electrode, wherein the polymer electrolyte includes the above-described block copolymer, the block copolymer may form a micelle structure. Characteristics of the polymer electrolyte are as described above.

The first electrode and the second electrode may refer to a configuration capable of supplying charge to the electrochromic layer. In one example, the transparent electrode may include any one or more of a transparent conductive oxide, a conductive polymer, an Ag nanowire, or a metal mesh. More specifically, ITO (Indium Tin Oxide), FTO (Fluor doped Tin Oxide), AZO (Aluminum doped Zinc Oxide), GZO (Galium doped Zinc Oxide), ATO (Antimony doped Tin Oxide), IZO (Indium doped Zinc Oxide) It may include one or more materials selected from the group consisting of, 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 may be used without limitation. For example, a transparent electrode may be provided by forming an electrode material including 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 within the range of 1 nm to 1 μm. The upper limit of the thickness of the transparent electrode is not particularly limited, but for the purpose of low resistance, 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% of visible light in order to sufficiently reflect the light transmittance of the electrochromic device.

In the present application, the electrochromic layer and the ion storage layer may include an electrochromic material undergoing a redox reaction, and the electrochromic material may exhibit color change and discoloration by redox reaction. Examples of electrochromic materials that can be used include conductive polymers, organic chromic materials and / or inorganic chromic materials. The conductive polymer may be polypyrrole, polyaniline, polypyridine, polyindole, polycarbazole, or the like, and an organic discoloration material may be a material such as viologen, anthraquinone, phenocyazine, but is not limited thereto. It is not.

In addition, the inorganic discoloration material may include one or more metal oxides of oxides of Ti, Nb, Mo, Ta, W, V, Cr, Mn, Co, Ni, Rh, and Ir. The electrochromic layer and the ion storage layer may include inorganic discoloring materials complementary to each other in the redox reaction. For example, a reducing inorganic discoloration material that is an oxide of Ti, Nb, Mo, Ta, and W in the electrochromic layer, specifically, one or more of TiO ₂ , Nb ₂ O ₅ , MoO ₃ , Ta ₂ O _5, and WO ₃ When the reducing inorganic discoloration material is included, the ion storage layer includes an oxidizing inorganic discoloration material which is an oxide of V, Cr, Mo, Co, Ni, Rh and Ir, specifically, V ₂ O ₅ , CrO ₃ , LixCoO ₂ , LiNiO _x (Wherein x is 1 to 3), an oxidative inorganic discoloration material of at least one of Rh ₂ O ₃ and IrO ₂ may be included.

In the present application, the term "reducible inorganic discoloration substance" means a substance which is colored by a reduction reaction, and the term "oxidative inorganic discoloration substance" means a substance which is colored by an oxidation reaction.

In another example, the electrochromic layer may have a transmittance of 10% to 30% for visible light when colored and a range of 55% to 75% for visible light when decolored. In addition, 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 within a range of 50 nm to 400 nm. If the thickness is less than 50 nm, it is difficult to sufficiently react for discoloration. If the thickness is greater than 150 nm, the electrochromic device of the thin film may not be provided, and the transmittance of the device may be reduced.

The ion storage layer may have a transmittance of 5% to 40% for visible light when colored and a range of 45% to 80% for visible light when decolored. In addition, 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 within the range of 10 nm to 400 nm. When the thickness is less than 10 nm, it is difficult to sufficiently react for discoloration. When the thickness is greater than 150 nm, the electrochromic device of the thin film may not be provided, and the transmittance of the device may be reduced.

According to the present application, a polymer electrolyte comprising a micellar block copolymer and a crosslinked polymer matrix exhibits excellent ionic conductivity. In addition, the polymer electrolyte of the present application can improve the optical properties and bi-stability of the electrochromic device when applied to the electrochromic device, it can improve the long-term durability.

1 is a view schematically showing a block copolymer of the present application.
2 is a measurement result confirming the micelle structure of the block copolymer synthesized in Preparation Example 1.
3 is a measurement result for confirming the micelle structure of the block copolymer synthesized in Preparation Example 2. FIG.
Figure 4 is a graph measuring the characteristics of the electrochromic device according to the type of 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 with reference to Examples, but the scope of the polymer electrolyte is not limited by the Examples described below.

Physical properties in this Example and Comparative Example were evaluated in the following manner.

Production Example  1. Preparation of Block Copolymer (A1)

3 equivalents of triethylamine (TEA) and 2-bromo isobutryl relative to 1 equivalent of terminal hydroxy (mPEG-OH) of polyethyleneglycol for the preparation of initiators for Atom Transfer Radical Polymerization (ATRP) Add 2 equivalents of 2-bromo isobutyryl bromide and react. The reactant was dissolved in diethyl ether solvent to remove impurities to recover the precipitate, which was repeated twice and dried.

The prepared initiator has bromine at the end of the polyethylene glycol (PEG) polymer, which is dissolved in ethanol, a reaction solvent, and 43 parts by weight of methyl methacrylate and 4.75 parts by weight of hydroxy propyl methacrylate. The flask is sealed with a rubber film and bubbling nitrogen for 30 minutes while stirring at room temperature to remove dissolved oxygen. Thereafter, the flask was immersed in a 60 ° C. oil bath, a catalyst solution and a catalyst reducing agent were added thereto, and the reaction was performed for 24 hours. As a 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-dimethyl valeronitryl) (V-65) was used.

The prepared black polymer is dissolved in ethyl acetate. It was immersed in an oil bath set at 60 ° C. under oxygen pressure, and then 1 equivalent of 2-isocyanatoethyl acrylate (AOI) and dibutyl to the hydroxy functional group of the hydroxy propyl methacrylate. 0.1 equivalent of tin dilaurate (DBTDL) was added thereto, followed by stirring for 4 hours. The acryloyl group was introduced by urethane reaction of the hydroxy functional group with an isocyanate group of 2-isocyanatoethyl acrylate. After the reaction was completed, precipitated and purified in a cold isopropyl alcohol: hexane = l: l mixed solution.

Production 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 at the ratios shown in Table 1 below.

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

PEO: Polyethylene Oxide

PMMA: Poly methyl methacrylate

AOI: isocyanatoethyl acrylate (2-Isocyanatoethyl acrylate)

DMAEMA: 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 preparation was dissolved in 10 g of a polycarbonate solvent, and particle size analysis (DLS) measurements were performed after 24 hours. The size of the micelles of the polyethylene oxide-polymethyl methacrylate block copolymers is known and has a size of about 300 to 400 nm.

The measurement results of Preparation Example 1 (A1) are shown in FIG. 2, and since about 48% of particles having a size of 371.5 d · nm exist in the solution, 48% of the total block copolymers may form a micelle structure.

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

(2) molecular weight and composition ratio

The block ratio and molecular weight of the prepared block polymer were evaluated by the following method, and are shown in Table 1 above.

Specifically, after the solidification through the purification step of the polymer solution completely removed the catalyst, 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 through an alumina column to remove the copper complex catalyst, followed by dropwise addition of excess diethyl ether while stirring to solidify by removing residual monomer. The solidified polymer was dried in a vacuum oven for 24 hours. The block polymer purified by the above method was dissolved in CDCl ₃ solvent and measured by nuclear magnetic resonance ( ¹ H NMR) analysis equipment. As a result, the 1H peak derived from CH ₂ = C (CH ₃ )-at the end of the acrylate monomer double bond was not confirmed, and it was confirmed that no unreacted monomer was present. In addition, a 3H peak derived from -OCH ₃ at the end of the ethylene glycol block was found in the vicinity of 3.2 ppm, and the ratio and the molecular weight of each polymer block were calculated based on this. Approximately 450 H peaks (113 4H X repeating units) derived from -CH ₂ CH ₂ O- of the ethylene glycol formed of the polymer appear in the 3.6 to 3.8 ppm region, and are adjacent to the main chain of methyl methacrylate formed of the polymer. Since the 3H peak derived from CH3 appeared in the 3.5 to 3.6 ppm region, the area ratio thereof was calculated to calculate the content of each constituent monomer as a mass fraction. 2H peaks derived from -OCH ₂ -adjacent to dimethylaminoethyl methacrylate and 2-isocyanatemethyl acrylate COO- formed of the polymer appear in the range of 4.0 to 4.2 ppm and 3.9 to 4.0 ppm, respectively. The content of monomers was calculated by mass fraction.

Example  One

Preparation of Coating Liquid

600rpm so that a mixture of 1.25 g of the block copolymer (A1) prepared in Preparation Example 1, 10 g of a lithium salt and a solvent, 3.75 g of a glycol-based oligomer, 0.3 g of a crosslinkable monomer, and 0.03 g of a photoinitiator was mixed well using a homogenizer. Mix for 3 hours or more. Then, open the lid of the container slightly to remove the bubbles generated in the solution and leave for 3 hours. The whole process takes place in a yellow room with UV protection.

Preparation of Polymer Electrolyte

The coating solution is coated in a certain amount between the release film and then the film is covered. After that, make a uniform thickness using Bakers applicator. When placed in a UV curing apparatus and cured for 1 minute, a polymer electrolyte in a freestanding film state can be obtained. Permeability, turbidity, ion conductivity, etc. of the formed polymer electrolyte were measured.

Preparation of Electrochromic Device

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

Example  2 and Comparative example  1 to 2

A polymer electrolyte was prepared in the same manner as in Example 1 except that each component and the ratio of the coating solution were adjusted as shown in Table 2 below.

Lithium salt and solvent (g) Block copolymer (g) Glycol-based oligomers (g) Crosslinkable monomer (g) 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 (1M concentration, 1.66 g of lithium salt dissolved in 8.34 g of propylene carbonate solvent)

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

Crosslinkable monomer: AA (acrylic acid)

Photoinitiator: Irgacure 819 (manufactured by Ciba)

2. Characterization of Electrochromic Device

(1) ion conductivity

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

(2) permeability and turbidity

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

(3) Color transmittance and decolorization transmittance

Applying voltages of -2V and + 2V to the electrochromic device every 100 seconds was set as one cycle. Transmittance during coloring / bleaching was measured based on the 550nm wavelength of the UV-Vis spectrum when the voltage was applied for 90 seconds or more in the coloring or decolorizing state.

(4) Bistable  Test( Bistability  Test)

After the voltage was applied to the electrochromic device to make it decolorized, the applied voltage was cut off and the change of transmittance with time was measured.

(5) durability evaluation

A voltage of -2V and + 2V was applied every 50 seconds to the electrochromic device using a potentiometer. The cycle was repeated to determine the amount of charge.

Physical property evaluation results for each of the Examples and Comparative Examples are as shown in Table 3, Table 4 and FIG.

Permeability (%) Turbidity (%) Ion Conductivity (S / cm) Reliability Example 1 95.3 1.2 1.39 × 10 ^-3 ○ Example 2 95.0 1.6 1.42 × 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 transmittance (%) Decolorization transmittance (%) △ T 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 when decolorized-visible light transmittance when colored

As can be seen in Tables 3 and 4, both Examples and Comparative Examples have high transmittance and low turbidity to ensure transparency. It can be seen that the difference in the visible light transmittance is large when the color and the electrochromic device when used as an excellent performance. In addition, as shown in FIG. 4, an electrochromic device having excellent bistability may be provided, and as illustrated in FIG. 5, an electrochromic device having excellent long-term durability may be provided.

Claims (14)

A first block comprising at least 55 wt% of a block represented by Formula 1; And a monomer having a crosslinkable functional group and a unit represented by the following Chemical Formula 2, wherein the unit of Chemical Formula 2 includes a second block having 55% by weight or more of the block, and includes a block copolymer forming a micelle structure.
The second block forms a core of the micelle structure,
A polymer electrolyte in which the core of the micelle structure forms a crosslinked structure:
[Formula 1]

[Formula 2]

In Formula 1, A is an alkylene group having 1 to 8 carbon atoms, Q in Formula 2 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 having 6 to 32 carbon atoms or a carboxyl group.
The polymer electrolyte of claim 1, wherein the second block of the block copolymer further comprises a unit represented by Formula 3 below:
[Formula 3]

In Formula 3, 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 And hydrogen, an alkyl group having 1 to 32 carbon atoms, an aromatic hydrocarbon or carboxyl group having 6 to 32 carbon atoms, and m is an integer of 1 to 20.
The polymer electrolyte of claim 1, wherein the block copolymer has a mass ratio of the first block and the second block of 1: 9 to 9: 1.
delete The polymer electrolyte of claim 1, wherein the block copolymer has a molecular weight distribution (PDI) of about 1.0 to about 1.3.
The polymer electrolyte according to claim 1, comprising 1 to 20 parts by weight of the block copolymer based on 100 parts by weight of the total polymer electrolyte.
The polymer electrolyte of claim 1, further comprising a glycol-based oligomer.
8. 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.
The method of claim 1, wherein 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} ) (where a and b are natural numbers), LiOC ( At least one compound selected from the group consisting of 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; A polymer electrolyte further comprising.
The polymer electrolyte of claim 1, further comprising a polar solvent.
The polymer electrolyte of claim 10, wherein the polar solvent is at least one of a carbonate compound, an ether compound, and an ester compound.
The polymer electrolyte of claim 1, further comprising a crosslinkable monomer.
delete A first electrode; Electrochromic layer; Claim 1 polymer electrolyte; Ion storage layer; And a second electrode.

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