Color changing polymer composition and electrochromic device comprising the same

Abstract

Disclosed are color-changing polymer compositions, ionically conductive compositions, transparent electrode layer compositions, and electrochromic devices including the same, which can be used in a paint-type spray process. The color-changing polymer compositions for electrochromic devices include a color-changing material in an amount of about 5 wt% to 30 wt% of the total weight of the composition, a ferrocene in an amount of about 0.01 wt% to 1 wt%, a polymer matrix in an amount of about 10 wt% to 30 wt%, an ionically conductive material in an amount of about 20 wt% to 70 wt%, and a POSS (polyhedral oligomeric silsesquioxane) derivative in an amount of about 1 wt% to 10 wt%.

Description

Technical Field

[0001] This invention relates to color-changing polymer compositions, ion-conducting compositions, transparent electrode layer compositions, and electrochromic devices comprising the same. The color-changing polymer compositions, ion-conducting compositions, and transparent electrode layer compositions can be applied to paint-type spray coating processes. Background Technology

[0002] Recently, the importance of color in marketing has increased across various sectors, including home appliances and mobile devices. Particularly in the automotive industry, the need for color in marketing purposes demands a focus on luxury and differentiation. Therefore, there is an ongoing experimentation with electrochromic colors to offer novel options.

[0003] Electrochromism is a phenomenon in which a reversible color change occurs when an electrode material undergoes an electrochemical oxidation or reduction reaction. For example, when Li... + or H + When electrons are injected into WO3 (a typical reduction coloring material), it forms a color due to electrochromism, and returns to transparency after the electrons are released. However, for oxidation coloring materials (such as MnO, LiO, etc.), the color changes upon the release of LiO. + or H + It forms a color after reacting with electrons, and regains its transparency after injection.

[0004] Typical electrochromic devices are provided in the form of a stacked structure of substrate / conductive layer / ionic electrolyte and color-changing material layer / conductive layer / substrate.

[0005] However, conventional electrochromic devices are limited by the materials used to form the layers and the methods of their formation. They must be formed on a smooth, flat substrate (such as glass or a thin film), making it difficult to use a wide variety of substrate materials. Furthermore, when applied to substrate materials with distorted surfaces, it is impossible to fabricate and form the material on them.

[0006] Details are provided as background art statements to better understand the background of the invention, and should not be construed as an admission that the described details correspond to conventional art known to those skilled in the art. Summary of the Invention

[0007] In a preferred aspect, color-changing polymer compositions, ion-conducting compositions, and transparent electrode layer compositions for coating-type spraying processes are provided, as well as electrochromic devices comprising the same.

[0008] In one aspect, a color-changing polymer composition for use in electrochromic devices is provided. The color-changing polymer composition may comprise: a color-changing material in an amount of about 5% to 30% by weight; ferrocene in an amount of about 0.01% to 1% by weight; a polymer matrix in an amount of about 10% to 30% by weight; an ion-conducting material in an amount of about 20% to 70% by weight; and a POSS (polyhedral oligomeric silsesquioxane) derivative in an amount of about 1% to 10% by weight; the weight percentages are based on the total weight of the composition.

[0009] The color-changing material may suitably include octahexylviologen polyhedral oligomeric silsesquioxane (OHV-POSS), which contains 1 to 8 monohexylviologen groups on the reactive functional groups of POSS (cage-type polysilsesquioxane).

[0010] The ferrocene may suitably include ferrocene substituted with alkyl groups.

[0011] The polymer matrix may suitably include one or more selected from polyvinylidene fluoride (PVDF) and its derivatives, polymethyl methacrylate (PMMA) and its derivatives, and polyvinyl alcohol (PVA).

[0012] The ion-conducting material may include one or more of room-temperature ionic liquids and lithium salts.

[0013] The POSS (cage-type polysilsesquioxane) derivative may include one or more groups selected from alkyl, vinyl, and glycidyl groups.

[0014] The color-changing polymer composition may further include a solvent component, and the solvent component may include one or more selected from isopropanol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).

[0015] In one aspect, an ion-conducting composition for electrochromic devices is provided. The ion-conducting composition may comprise: a polymer matrix in an amount of 20% to 40% by weight; a reactive POSS (cage-type polysilsesquioxane) material in an amount of 20% to 40% by weight; and a lithium salt in an amount of 20% to 40% by weight; the weight percentages are based on the total weight of the composition.

[0016] The polymer matrix may suitably include one or more selected from polyvinylidene fluoride (PVDF) and its derivatives, polymethyl methacrylate (PMMA) and its derivatives, and polyvinyl alcohol (PVA).

[0017] The reactive POSS material may suitably include one or more selected from glycidyl POSS, acrylic POSS, octaphenyl POSS, isocyanate POSS, and alkyl POSS.

[0018] The ion-conducting composition may further comprise 20% by weight or less of a room-temperature ionic liquid. Furthermore, the ion-conducting composition may include a solvent component, and the solvent component may suitably include one or more selected from isopropanol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).

[0019] In one aspect, a transparent electrode layer composition for an electrochromic device is provided. The transparent electrode layer composition may comprise: a silver nanowire suspension in an amount of about 30% to 80% by weight; a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) suspension in an amount of about 10% to 60% by weight; glycerol in an amount of about 0.001% to 10% by weight; ethylene glycol in an amount of about 0.001% to 10% by weight; dodecylbenzenesulfonic acid in an amount of about 0.001% to 10% by weight; divinyl sulfone in an amount of about 0.001% to 10% by weight; and dimethyl sulfoxide in an amount of about 0.001% to 10% by weight. The silver nanowire suspension may include about 1% silver nanowires, and the PEDOT:PSS suspension may include about 1% to 2% poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid).

[0020] The term “silver nanowire (1%) suspension” refers to a silver nanowire suspension comprising about 1% by weight of silver nanowires, and the term “PEDOT:PSS (1% to 2%) suspension” refers to a PEDOT:PSS suspension comprising about 1% to 2% by weight of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid).

[0021] The transparent electrode layer composition may further include a solvent component, and the solvent component may suitably include one or more selected from isopropanol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).

[0022] In one aspect, an electrochromic device is provided. The electrochromic device may include a color-changing layer formed of a color-changing polymer composition, a first electrode layer, and a second electrode layer, the color-changing polymer composition comprising, by weight of about 5% to 30% of a color-changing material, by weight of about 0.01% to 1% of ferrocene, by weight of about 10% to 30% of a polymer matrix, by weight of about 20% to 70% of an ion-conducting material, and by weight of about 1% to 10% of a POSS (cage-type polysilsesquioxane) derivative, the first electrode layer and the second electrode layer being formed on corresponding surfaces of the color-changing layer.

[0023] Each of the first electrode layer and the second electrode layer may be formed of a transparent electrode layer composition comprising: a silver nanowire (1%) suspension in an amount of about 30% to 80% by weight, a PEDOT:PSS (1% to 2%) suspension in an amount of about 10% to 60% by weight, glycerol in an amount of about 0.001% to 10% by weight, ethylene glycol in an amount of about 0.001% to 10% by weight, dodecylbenzenesulfonic acid in an amount of about 0.001% to 10% by weight, divinyl sulfone in an amount of about 0.001% to 10% by weight, and dimethyl sulfoxide in an amount of about 0.001% to 10% by weight.

[0024] The electrochromic device may further include an ion-conducting layer formed between the color-changing layer and the first electrode layer.

[0025] The ion-conducting layer may be formed from an ion-conducting composition comprising: a polymer matrix in an amount of about 20% to 40% by weight of the total weight of the ion-conducting composition, a reactive POSS (cage-type polysilsesquioxane) material in an amount of about 20% to 40% by weight, a lithium salt in an amount of about 20% to 40% by weight, and a room-temperature ion liquid in an amount of about 0% to 20% by weight (excluding 0% by weight).

[0026] The electrochromic device may further include a transparent coating formed on the surface of the first electrode layer.

[0027] The transparent coating may suitably include one or more selected from polycarbonate, polystyrene, polyethylene and polyester.

[0028] The electrochromic device may further include a silver mesh layer formed between the first electrode layer and the transparent coating.

[0029] According to various exemplary embodiments of the present invention, by developing corresponding compositions that can be used in a spraying process for coatings to form the color-changing layer, ion-conducting layer and electrode layer constituting an electrochromic device, it is anticipated that the effect of manufacturing electrochromic devices with various structures can be achieved.

[0030] Other aspects of the invention are disclosed below. Attached Figure Description

[0031] Figure 1 An exemplary electrochromic device according to an exemplary embodiment of the present invention is shown;

[0032] Figure 2 An exemplary electrochromic device according to an exemplary embodiment of the present invention is shown; and

[0033] Figure 3 An exemplary electrochromic device according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0034] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to include the plural forms as well. It should be further understood that when the terms “comprising” and / or “including” are used in this specification, they specify the presence of the stated features, values, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes any and all combinations of one or more of the listed related items.

[0035] Unless otherwise specified or obvious from the context, the term “about” as used herein is understood to mean within the normal tolerance range in the field, such as within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. All numerical values ​​provided herein are modified by the term “about” unless the context clearly indicates otherwise.

[0036] It should be understood that, as used herein, the terms "vehicle" or "of a vehicle" or other similar terms generally include motor vehicles, such as passenger vehicles including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, vessels including various boats and ships, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels derived from non-petroleum sources). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a vehicle that combines gasoline and electric power.

[0037] In this specification, when describing the range of a variable, it will be understood that the variable includes all values ​​contained within the endpoints described in the range. For example, the range “5 to 10” will be understood to include any subranges (e.g., 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc.) and the individual values ​​of 5, 6, 7, 8, 9, and 10, and will also be understood to include any value between valid integers within the range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, etc. Similarly, the range “10% to 30%” will be understood to include subranges such as 10% to 15%, 12% to 18%, 20% to 30%, etc., and all integers including values ​​up to 30% such as 10%, 11%, 12%, 13%, etc., and will also be understood to include any value between valid integers within the range, such as 10.5%, 15.5%, 25.5%, etc.

[0038] In the following detailed description of embodiments of the invention, with reference to the accompanying drawings, we will give a detailed description of the invention. However, the invention is not limited to the following embodiments and can be modified to have various different forms. These embodiments are provided to complete the disclosure of the invention and to fully describe the invention to those skilled in the art.

[0039] As used herein, the term "color-changing polymer composition" refers to a composition used to form a color-changing layer in an electrochromic device. The color-changing polymer composition may further include a solvent component to form the color-changing layer using a spray coating process. Specifically, the color-changing polymer composition can change its color in response to voltage and current applied thereto.

[0040] The color-changing polymer composition may comprise, by weight of the total composition, 5% to 30% of a color-changing material, 0.01% to 1% of ferrocene, 10% to 30% of a polymer matrix, 20% to 70% of an ion-conducting material, and 1% to 10% of a POSS (cage-type polysilsesquioxane) derivative.

[0041] The color-changing polymer composition containing the above-mentioned amounts of components may further contain or be mixed with solvent components, thereby being used as a coating for spraying purposes.

[0042] A color-changing polymer composition containing a solvent component that can be used in coatings may comprise: 0.1% to 10% by weight of a color-changing material, 0.01% to 1% by weight of ferrocene, 0.1% to 10% by weight of a polymer matrix, 0.1% to 10% by weight of an ion-conducting material, 0.1% to 5% by weight of a POSS (cage-type polysilsesquioxane) derivative, and the balance being a solvent.

[0043] Preferably, the color-changing polymer composition containing the solvent component may comprise: 0.1% to 2.0% by weight of the color-changing material, 0.01% to 0.05% by weight of ferrocene, 1.0% to 3.0% by weight of the polymer matrix, 4% to 10% by weight of the ion-conducting material, 0.3% to 0.7% by weight of the POSS (cage-type polysilsesquioxane) derivative, and 80% to 92% by weight of the solvent, based on the total weight of the composition.

[0044] The color-changing material may suitably include octahexylviolin cage-like polysilsesquioxane (OHV-POSS), which contains 1 to 8 monohexyl-violin substituted on the reactive functional groups of POSS (cage-like polysilsesquioxane). In particular, various colors, such as blue, green, and red, can be achieved by changing the chemical structure of the color-changing material. When the amount of the color-changing material is less than the aforementioned lower limit, the apparent color change deteriorates, while when the amount of the color-changing material is greater than the aforementioned upper limit, the solution becomes saturated and aggregates, leading to reduced solubility.

[0045] The ferrocene used in this article is an oxidizing agent. Preferably, the ferrocene may include alkyl-substituted ferrocene. When the amount of ferrocene is less than the lower limit mentioned above, the redox reaction will be unbalanced, and therefore the color change stability will be worse. When the amount of ferrocene is greater than the upper limit mentioned above, the neutral transmittance will decrease due to its inherent yellow color.

[0046] The polymer matrix may suitably include one or more selected from polyvinylidene fluoride (PVDF) and its derivatives, polymethyl methacrylate (PMMA) and its derivatives, and polyvinyl alcohol (PVA). When the amount of polymer matrix is ​​less than the lower limit mentioned above, it is insufficient to form a film, while when the amount of polymer matrix is ​​greater than the upper limit, the activity of the color-changing layer will decrease, resulting in poor color-changing performance.

[0047] The ion-conducting material may suitably include one or more of room-temperature ionic liquids and lithium salts. When the amount of ion-conducting material is less than the lower limit mentioned above, the ion conductivity is low, and therefore no color change occurs. However, when the amount of ion-conducting material is greater than the upper limit mentioned above, the mechanical properties of the color-changing layer deteriorate.

[0048] The POSS derivatives used in this paper can improve the mechanical strength and conductivity of the color-changing layer, and may include one or more substituent groups selected from alkyl, vinyl, and glycidyl groups. When the amount of the POSS derivative is less than the lower limit mentioned above, curing is reduced, while when the amount is greater than the upper limit mentioned above, the time required for color change is prolonged due to reduced movement of electrons and ions.

[0049] A color-changing polymer composition for spray coatings may be prepared by including or mixing with a solvent component. The solvent component may suitably include one or more selected from isopropanol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). When the amount of solvent is less than the lower limit mentioned above, nozzle clogging frequently occurs during spraying, while when the amount of solvent is greater than the upper limit mentioned above, film formation and curing are delayed due to the low concentration.

[0050] As used herein, the term "ionically conductive composition" refers to a composition used to form an ionically conductive layer in an electrochromic device. The ionically conductive composition may further comprise or be mixed with a solvent component to form the ionically conductive layer using a spray coating process.

[0051] The ion-conducting composition may suitably comprise about 20% to 40% by weight of a polymer matrix, about 20% to 40% by weight of a reactive POSS (cage-type polysilsesquioxane) material, and about 20% to 40% by weight of a lithium salt. The ion-conducting composition may further comprise about 20% by weight or less of a room-temperature ionic liquid.

[0052] The ion-conducting composition may contain a solvent component or be a coating mixed with a solvent component for spraying purposes. The ion-conducting layer formed by spraying an ion-conducting composition containing the aforementioned amounts of components has high surface hardness and is therefore not damaged during the additional spraying process to form the electrode layer.

[0053] The ion-conducting composition containing a solvent component may suitably comprise, by weight of about 5% to 20% of a polymer matrix, by weight of about 5% to 20% of a reactive POSS (cage-type polysilsesquioxane) material, by weight of about 5% to 20% of a lithium salt, and the balance being a solvent. Furthermore, by weight of the composition, the ion-conducting composition may further comprise, by weight of about 20% or less of a room-temperature ionic liquid.

[0054] Preferably, the ion-conducting composition containing the solvent component may suitably contain: a polymer matrix in an amount of about 5% to 15% by weight, a reactive POSS material in an amount of about 5% to 15% by weight, a lithium salt in an amount of about 5% to 15% by weight, and a solvent in an amount of about 80% to 96% by weight.

[0055] The polymer matrix may suitably include one or more selected from polyvinylidene fluoride (PVDF) and its derivatives, polymethyl methacrylate (PMMA) and its derivatives, and polyvinyl alcohol (PVA). When the amount of polymer matrix is ​​less than the lower limit mentioned above, it is insufficient to form a film, while when the amount of polymer matrix is ​​greater than the upper limit mentioned above, the activity of the ion-conducting layer will decrease, resulting in poor color-changing performance.

[0056] The reactive POSS material may suitably include one or more selected from glycidyl POSS, acrylic POSS, octaphenyl POSS, isocyanate POSS, and alkyl POSS. When the amount of reactive POSS material is less than the lower limit mentioned above, the degree of curing during the formation of the ion-conducting layer will decrease, while when the amount of reactive POSS material is greater than the upper limit mentioned above, the time required for color change will be prolonged due to the reduced movement of electrons and ions.

[0057] Lithium salts can form ions that move within the ion-conducting layer. When the amount of lithium salt is below the aforementioned lower limit, the ionic conductivity may decrease, while when the amount of lithium salt is above the aforementioned upper limit, the transmittance will decrease due to saturation, and the apparent color change will decrease. Here, the lithium salt may suitably include those selected from LiPF6, LiBF4, LiClO4, LiCl, LiBr, LiI, and LiB. 10 Cl 10 Two or more of the following: LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, LiN(SO2C2F5)2, Li(CF3SO2)2N, LiC4F9SO3, LiB(C6H5)4, Li(SO2F)2N(LiFSI), and (CF3SO2)2NLi.

[0058] The coating may contain a solvent component or be mixed with a solvent component to prepare an ion-conducting composition for use in spray coatings. The solvent component may suitably include at least one selected from isopropanol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). When the amount of solvent is less than the lower limit mentioned above, nozzle clogging frequently occurs during spraying, while when the amount of solvent is greater than the upper limit mentioned above, film formation and curing are delayed due to the low concentration.

[0059] The term "transparent electrode layer composition" refers to a composition used to form the electrode layer of an electrochromic device. The transparent electrode layer composition may contain solvent components or be mixed with solvent components to form the electrode layer using a spray coating process.

[0060] The transparent electrode layer composition comprises, by weight of the total composition, about 30% to 80% of a silver nanowire (1%) suspension, about 10% to 60% of a PEDOT:PSS (1% to 2%) suspension, about 0.001% to 10% of glycerol, about 0.001% to 10% of ethylene glycol, about 0.001% to 10% of dodecylbenzenesulfonic acid, about 0.001% to 10% of divinyl sulfone, and about 0.001% to 10% of dimethyl sulfoxide.

[0061] Preferably, the transparent electrode layer composition may comprise, by weight of the total composition, about 30% to 50% of a silver nanowire (1%) suspension, about 39% to 59% of a PEDOT:PSS (1% to 2%) aqueous suspension, about 5% to 7.5% of glycerol, about 2.5% to 3.75% of ethylene glycol, about 0.25% to 0.375% of dodecylbenzenesulfonic acid, about 0.25% to 0.375% of divinyl sulfone, and about 2.5% to 3.75% of dimethyl sulfoxide.

[0062] The transparent electrode layer composition may further contain a solvent or a coating that is mixed with a solvent for spraying.

[0063] The transparent electrode layer composition containing solvent components may comprise, by weight of the total composition, a suspension of silver nanowires (1%) in an amount of about 1% to 30% by weight, a suspension of PEDOT:PSS (1% to 2%) in an amount of about 1% to 30% by weight, glycerol in an amount of about 0.001% to 3% by weight, ethylene glycol in an amount of about 0.001% to 3% by weight, dodecylbenzenesulfonic acid in an amount of about 0.001% to 3% by weight, divinyl sulfone in an amount of about 0.001% to 3% by weight, dimethyl sulfoxide in an amount of about 0.001% to 3% by weight, and the balance being solvent.

[0064] When the amount of silver nanowire (1%) suspension is less than the lower limit mentioned above, the conductivity will decrease, while when the amount is greater than the upper limit mentioned above, the transmittance will decrease.

[0065] When the amount of PEDOT:PSS (1% to 2%) suspension is less than the lower limit mentioned above, the conductivity will decrease and the surface roughness of the electrode layer will worsen. When the amount of PEDOT:PSS (1% to 2%) is greater than the upper limit mentioned above, a blue color will appear, thus reducing the apparent color change.

[0066] Glycerin and ethylene glycol are used as additives for PEDOT:PSS (1% to 2%) suspensions. When the amounts of glycerin and ethylene glycol fall within the aforementioned range, excellent effects on improving the conductivity of the PEDOT:PSS (1% to 2%) suspension can be obtained. However, when their amounts fall outside the aforementioned range, the effect on improving conductivity becomes less pronounced, and the conductivity of the electrode layer decreases.

[0067] When the amount of dodecylbenzenesulfonic acid is less than the lower limit mentioned above, the dispersibility of the solution will deteriorate, while when the amount is greater than the upper limit mentioned above, agglomeration will occur due to the reaction with the PEDOT:PSS (1% to 2%) suspension.

[0068] Divinyl sulfone can harden the surface of the electrode layer through a crosslinking reaction with additives. When the amount of divinyl sulfone is less than the lower limit mentioned above, curing will be insufficient, while when the amount exceeds the upper limit mentioned above, over-curing will occur.

[0069] A transparent electrode layer composition for use in spray coatings may be prepared by including or mixing with a solvent component. The solvent component may suitably include one or more selected from isopropanol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). When the amount of solvent is less than the lower limit mentioned above, nozzle clogging frequently occurs during spraying, while when the amount of solvent is greater than the upper limit mentioned above, film formation and curing are delayed due to the low concentration.

[0070] Using the color-changing polymer composition, ion-conducting composition, and transparent electrode layer composition described above, a laminated electrochromic device can be fabricated by spraying. In particular, since the spraying process can be applied, electrochromic devices can be formed on a variety of different substrate materials, and the configuration of the substrate can be eliminated.

[0071] Figure 1 An exemplary electrochromic device according to an exemplary embodiment of the present invention is shown. Figure 2 An exemplary electrochromic device according to an exemplary embodiment of the present invention is shown, and Figure 3 An exemplary electrochromic device according to an exemplary embodiment of the present invention is shown.

[0072] like Figure 1 As shown, the electrochromic device includes a color-changing layer 200, a first electrode layer 100, and a second electrode layer 300. The color-changing layer is formed of a color-changing polymer composition, and the first electrode layer 100 and the second electrode layer 300 are formed of a transparent electrode layer composition on the respective surfaces of the color-changing layer 200.

[0073] In addition, such as Figure 2 As shown, the electrochromic device may further include an ion-conducting layer 400 and a transparent coating 500, wherein the ion-conducting layer 400 is formed of an ion-conducting composition between the color-changing layer 200 and the first electrode layer 100, and the transparent coating 500 is formed on the surface of the first electrode layer 100.

[0074] In addition, such as Figure 3 As shown, the electrochromic device may further include a silver mesh layer 600 and a substrate 700, the silver mesh layer 600 being formed between a first electrode layer 100 and a transparent coating 500, and the substrate 700 being formed below a second electrode layer 300.

[0075] The color-changing layer 200 is a layer that actually changes color in response to voltage and current applied thereto, and can be formed by mixing a color-changing polymer composition as described above. For example, the color-changing polymer composition may contain about 5% to 30% by weight of a color-changing material, about 0.01% to 1% by weight of ferrocene, about 10% to 30% by weight of a polymer matrix, about 20% to 70% by weight of an ion-conducting material, about 1% to 10% by weight of a POSS (cage-type polysilsesquioxane) derivative, and a solvent component, and then be sprayed.

[0076] The color-changing layer 200 includes a color-changing material, which is an organic / inorganic mixture in which POSS, as an inorganic material, and viologen, as an organic material, are combined with each other. Electrochromic properties are imparted by substituting 1 to 8 monohexyl-viologen groups around the reactive organic functional groups of POSS as electrochromic materials. The advantages of octahexylviologen cage-type polysilsesquioxane (OHV-POSS) in the color-changing material are its short color-changing time, low-voltage actuation, and high color efficiency.

[0077] The first electrode layer 100 and the second electrode layer 300 are layers used as electrodes to transfer oxidation and reduction potentials, and can be formed by mixing the transparent electrode layer composition as described above and by spraying. For example, the transparent electrode layer composition may contain: a silver nanowire (1%) suspension in an amount of about 30% to 80% by weight of the total weight of the transparent electrode layer composition, a PEDOT:PSS (1% to 2%) suspension in an amount of about 10% to 60% by weight, glycerol in an amount of about 0.001% to 10% by weight, ethylene glycol in an amount of about 0.001% to 10% by weight, dodecylbenzenesulfonic acid in an amount of about 0.001% to 10% by weight, divinyl sulfone in an amount of about 0.001% to 10% by weight, dimethyl sulfoxide in an amount of about 0.001% to 10% by weight, and a solvent component. For example, an electrode layer with a mirror-like surface and a thin-film resistance of about 3Ω can be formed by spraying a coating solution obtained by mixing a transparent electrode layer composition with a solvent and then performing a low-temperature heat treatment (80°C).

[0078] The first electrode layer 100 and the second electrode layer 300 are transparent electrode layers, exhibiting a transmittance of 80% or higher due to the use of a composite material of poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) and silver nanowires. Furthermore, they exhibit relatively uniform and improved conductivity by filling the gaps between the silver nanowires (metallic material) with PEDOT:PSS (an organic conductive polymer material). Divinyl sulfone can be added as a crosslinking agent, thereby enabling the formation of independent conductive films through reaction with PEDOT:PSS, improving film stability, maintaining conductivity, and enhancing mechanical properties.

[0079] The ion-conductive layer 400 is a layer that stores ions to achieve a charge balance dependent on electron movement, and can be formed by mixing the ion-conductive composition as described above and by spraying. The ion-conductive composition may contain: a polymer matrix in an amount of about 20% to 40% by weight of the total weight of the ion-conductive composition, a reactive POSS (cage-type polysilsesquioxane) material in an amount of about 20% to 40% by weight, a lithium salt in an amount of about 20% to 40% by weight, and a solvent.

[0080] The ion-conducting layer 400 comprises a thermosetting ion-conducting layer composition using glycidyl-based POSS and electrolyte LiTFSI, thus allowing for the application of a paint-type spraying process, and by adding PVDF-HFP as a polymer matrix in the color-changing material layer, a thin film can be effectively formed.

[0081] Meanwhile, the polymer matrix, reactive POSS (cage-type polysilsesquioxane) material, and lithium salt exhibit the greatest ionic conductivity when mixed in a 1:1:1 weight ratio.

[0082] The transparent coating 500 is located on the outermost part of the electrochromic device to protect the electrochromic device and impart repeatable variable properties, and includes an acrylic composition that can be photocured or thermally solidified and has high surface hardness.

[0083] For example, the transparent coating 500 may include one or more selected from polycarbonate, polystyrene, polyethylene and polyester.

[0084] The time spent forming the silver grid layer 600 to change the color and pattern, and the silver grid layer 600 can be formed as a silver grid or a line structure.

[0085] The substrate 700 is the base material for forming the electrochromic device, and various substrates can be used. Since all the individual layers forming the electrochromic device can be formed by spraying, not only smooth, flat glass or thin-film substrates can be used, but also substrates with slightly rough surfaces, curved surfaces, or twisted structures. Therefore, this electrochromic device is expected to have wide applications and can be used in technical fields such as flexible displays.

[0086] Furthermore, the various layers forming the electrochromic device can be provided with design elements, such as patterns formed by using a mask during spraying.

[0087] Although various exemplary embodiments of the invention have been disclosed for illustrative purposes with reference to the accompanying drawings, the invention is not limited thereto but is defined by the appended claims. Therefore, those skilled in the art will understand that various modifications, additions, and substitutions can be made without departing from the scope and spirit of the invention as disclosed in the appended claims.

Claims

1. A color-changing polymer composition for an electrochromic device, comprising: a color-changing material in an amount of 5 to 30 weight percent; ferrocene in an amount of 0.01 to 1 weight percent; a polymer matrix in an amount of 10 to 30 weight percent; an ionically conductive material in an amount of 20 to 70 weight percent; and a cage polysilsesquioxane derivative in an amount of 1 to 10 weight percent, all weight percents based on the total weight of the color-changing polymer composition.

2. The color-changing polymer composition for electrochromic devices according to claim 1, wherein, the color-changing material comprises an octahexyl viologen cage polysilsesquioxane containing 1 to 8 monohexyl- viologens on the reactive functional groups of the cage polysilsesquioxane.

3. The color-changing polymer composition for electrochromic devices according to claim 1, wherein, the ferrocene comprises ferrocene substituted with alkyl groups.

4. The color-changing polymer composition for electrochromic devices according to claim 1, wherein, the polymer matrix comprises one or more selected from the group consisting of polyvinylidene fluoride and derivatives thereof, polymethyl methacrylate and derivatives thereof, and polyvinyl alcohol.

5. The color-changing polymer composition for electrochromic devices according to claim 1, wherein, the ionically conductive material comprises one or more selected from the group consisting of room temperature ionic liquids and lithium salts.

6. The color-changing polymer composition for electrochromic devices according to claim 1, wherein, the cage polysilsesquioxane derivative comprises one or more substituent groups selected from the group consisting of alkyl, vinyl, and glycidyl.

7. The color-changing polymer composition for electrochromic devices according to claim 1, wherein, the color-changing polymer composition further comprises a solvent component, and the solvent comprises one or more selected from the group consisting of isopropyl alcohol, ethanol, methanol, acetone, toluene, methyl ethyl ketone, ethyl acetate, methyl isobutyl ketone, dimethylformamide, and dimethyl sulfoxide.

8. An electrochromic device, comprising: a color-changing layer formed from a color-changing polymer composition comprising: a color-changing material in an amount of 5 to 30 weight percent, ferrocene in an amount of 0.01 to 1 weight percent, a polymer matrix in an amount of 10 to 30 weight percent, an ionically conductive material in an amount of 20 to 70 weight percent, and a cage polysilsesquioxane derivative in an amount of 1 to 10 weight percent, based on the total weight of the color-changing polymer composition; and first and second electrode layers formed on respective surfaces of the color-changing layer.

9. The electrochromic device of claim 8, wherein, each of the first and second electrode layers is formed from a transparent electrode layer composition comprising: a silver nanowire suspension in an amount of 30 to 80 weight percent, a PEDOT:PSS suspension in an amount of 10 to 60 weight percent, glycerol in an amount of 0.001 to 10 weight percent, ethylene glycol in an amount of 0.001 to 10 weight percent, dodecylbenzenesulfonic acid in an amount of 0.001 to 10 weight percent, divinyl sulfone in an amount of 0.001 to 10 weight percent, and dimethyl sulfoxide in an amount of 0.001 to 10 weight percent, based on the total weight of the transparent electrode layer composition.

10. The electrochromic device of claim 8, further comprising an ionically conductive layer formed between the color-changing layer and the first electrode layer.

11. The electrochromic device of claim 10, wherein, The ionically conductive layer is formed from an ionically conductive composition comprising: a polymeric matrix in an amount of 20 to 40 weight percent based on the total weight of the ionically conductive composition, a reactive caged poly silsesquioxane material in an amount of 20 to 40 weight percent, a lithium salt in an amount of 20 to 40 weight percent, and a room temperature ionic liquid in an amount of 0 to 20 weight percent, excluding 0 weight percent.

12. The electrochromic device of claim 8, further comprising a transparent coating layer formed on a surface of the first electrode layer.

13. The electrochromic device of claim 12, wherein, The transparent coating layer comprises one or more materials selected from polycarbonate, polystyrene, polyethylene, and polyester.

14. The electrochromic device of claim 12, further comprising a silver mesh layer formed between the first electrode layer and the transparent coating layer.

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