Electrochromic device and color changing method thereof

Abstract

The present invention discloses an electrochromic device and a color-changing method thereof. The electrochromic device comprises a first base (1), a first transparent conductive layer (2), a first electrochromic layer (3), an electrolyte layer (4), a second electrochromic layer (5), a second transparent conductive layer (6), and a second base (7), which are stacked in this order. The materials of the first electrochromic layer (3) and the second electrochromic layer (5) are either cathodic or anodic electrochromic materials. The color-changing method for the electrochromic device involves cycling a voltage opposite to or similar to the first voltage direction to a pretreated electrochromic device, thereby converting the electrochromic device between different colors. By combining a structure in which both electrochromic layers are either anodic or cathodic electrochromic materials with a specific color-changing method, color conversion between different colors can be achieved, expanding the range of electrochromic material options.

Description

[Technical field]

[0001] The present application belongs to the technical field of color-changing devices, and specifically relates to an electrochromic device and a color-changing method thereof. [Background technology]

[0002] Electrochromism refers to the phenomenon in which the optical properties of a material undergo a stable and reversible color transformation under the action of an applied electric field, and is expressed as a reversible transformation of color and transparency in appearance. Materials with electrochromic performance are called electrochromic materials, and devices made of electrochromic materials are called electrochromic devices. Electrochromic devices have very important application prospects in the fields of color-changing glasses, electronic displays, military concealment, building energy saving, etc.

[0003] Conventional electrochromic devices generally use a laminated structure of conductive layer-electrochromic layer-electrolyte layer-ion storage layer (electrochromic layer)-conductive layer. Among them, the electrochromic layer is one of the cores of electrochromic devices. The electrochromic materials constituting the electrochromic layer can be divided into inorganic electrochromic materials and organic electrochromic materials. Inorganic electrochromic materials, such as tungsten trioxide (WO3), vanadium pentoxide (V2O5), nickel oxide (NiO), and titanium dioxide (TiO2), have the advantages of stability and fast response. Organic electrochromic materials, such as viologen and polythiophene, have many varieties, rich colors, and are easy to design. Electrochromic materials can be divided into cathodic electrochromic materials and anodic electrochromic materials according to the color transformation. Cathodic electrochromic materials gain electrons and undergo a reduction reaction, allowing the color to change between coloring and fading, while anodic electrochromic materials lose electrons and undergo an oxidation reaction, allowing the color to change between coloring and fading.

[0004] At present, the manufacturing process of most electrochromic devices is complicated, and the color transformation is single, so it is difficult to meet the needs of multicolor display and personalization.In order to realize the color transformation of electrochromic devices, in the prior art, electrochromic devices are assembled by using cathodic electrochromic materials and anodic electrochromic materials that can be matched with each other in color transformation.For example, the electrochromic device can be realized to transform between red and blue by assembling a device using cathodic electrochromic materials whose color transformation range is between red and colorless, and anodic electrochromic materials whose color transformation range is between colorless and blue.

[0005] CN105278198A discloses a complementary inorganic all-solid-state electrochromic device and its manufacturing method. The device includes a substrate, a transparent conductive layer, an anodic electrochromic layer, an ion storage layer, a fast ion transport layer, a cathodic electrochromic layer and a transparent conductive layer arranged in order from bottom to top. CN105607375A discloses an electrochromic device of high-throughput sorting solid inorganic electrochromic materials and its manufacturing method. Each electrochromic device unit is plated from the bottom transparent conductive layer to the inside to the outside, a cathodic electrochromic layer, a solid electrolyte layer, an anodic electrochromic layer and an upper transparent layer in order. CN110109311A discloses an all-solid-state electrochromic device and its manufacturing method. The device is composed of a substrate A, a transparent conductive layer A, an anodic electrochromic layer, a solid electrolyte layer, a cathodic electrochromic layer, a transparent conductive layer B and a substrate B arranged in order. The cathodic electrochromic layer is a thin film of tungsten oxide doped with metal atoms, and the anodic electrochromic layer is a thin film of nickel oxide doped with metal atoms. Both of these electrochromic devices use a structure in which the cathodic electrochromic layer and the anodic electrochromic layer are combined.

[0006] However, the current electrochromic materials are few in number, and it is difficult to find a cathodic electrochromic material (or an anodic electrochromic material) that matches the color of the anodic electrochromic material (or a cathodic electrochromic material), so it is necessary to design and develop it independently, and the color matching may belong to the anodic electrochromic material or the cathodic electrochromic material. The electrochromic device of the above structure is easily limited by color, material or process in practical application, and is difficult to be widely used for the interconversion of more colors. Summary of the Invention

[0007] The present application provides an electrochromic device and its color changing method, which uses a structure in which both electrochromic layers are either anodic electrochromic materials or cathodic electrochromic materials, and combines a specific color changing method to realize conversion between different colors, expand the selection range of electrochromic materials, and facilitate the widespread use of more colors for interconversion, thereby meeting the needs of multicolor display and personalization.

[0008] In a first aspect, the present application provides an electrochromic device comprising, stacked in sequence, a first base, a first transparent conductive layer, a first electrochromic layer, an electrolyte layer, a second electrochromic layer, a second transparent conductive layer, and a second base, An electrochromic device is provided, wherein the materials of the first electrochromic layer and the second electrochromic layer are either cathodic electrochromic materials or anodic electrochromic materials.

[0009] In the electrochromic device according to the present application, both electrochromic layers use cathodic electrochromic materials or anodic electrochromic materials, and by combining a specific color change method, the materials of both electrochromic layers do not need to be limited to the combination of cathodic electrochromic materials and anodic electrochromic materials, and the range of electrochromic material selection can be expanded.

[0010] In one embodiment of the present application, the first transparent conductive layer and the second transparent conductive layer are each independently formed of at least one of indium-tin oxide (ITO), aluminum zinc oxide (AZO), fluorine doped tin oxide (FTO), silver nanowires, graphene, carbon nanotubes, metal grids, and silver nanoparticles.

[0011] In one embodiment of the present application, the first transparent conductive layer and the second transparent conductive layer each independently have a thickness of 1 to 1000 nm, and may be, for example, 1 nm, 2 nm, 5 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 50 nm, 70 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, or 1000 nm.

[0012] In this field, cathodic electrochromic materials include cathodic electrochromic reduced state coloring materials, cathodic electrochromic oxidized state coloring materials and cathodic electrochromic pleochroic materials.

[0013] Anodic electrochromic materials include anodic electrochromic reduced state coloring materials, anodic electrochromic oxidized state coloring materials, and anodic electrochromic pleochroic materials.

[0014] As used herein, cathodic electrochromic reduced state coloring materials are initially colorless and become colored upon electron gain reduced state. Such materials include TiO2, WO3, Nb2O5, MoO3, Ta2O5, viologens and their derivatives, and the like.

[0015] Cathodic electrochromic oxidized state coloring materials are initially colored and become colorless upon electron gain reduction, such materials include Prussian blue and its derivatives, Ruthenium purple and its derivatives, etc.

[0016] The color transformation of the cathodic electrochromic multicolor material may be a multicolor transformation, for example, with an initial state of color a, an intermediate state of electron gain of color b, and a reduced state of electron gain of color c, or a two-color transformation, for example, with an initial state of color a', and a reduced state of electron gain of color c'. Such materials are suitable for use with CoO x , Rh2O3, ferrocene and its derivatives, etc.

[0017] Anodic electrochromic reduced state colored materials have an initial colored state and an electron-loss oxidized state that is colorless. Such materials include polythiophenes and their derivatives.

[0018] Anodic electrochromic oxidation state coloring materials have an initial colorless state and an electron-loss oxidation state that is colored. Such materials include NiO, IrO2, polytriphenylamine and its derivatives, etc.

[0019] The color transformation of the anodic electrochromic multicolor material may be a multicolor transformation, for example, with an initial state of color d, an electron-loss intermediate state of color e, and an electron-loss oxidation state of color f, or a two-color transformation, for example, with an initial state of color d' and an electron-loss oxidation state of color f'. Such materials include V2O5, MnO2, polyaniline and its derivatives, polypyrrole and its derivatives, etc.

[0020] The materials of the first electrochromic layer and the second electrochromic layer of the electrochromic device of the present application can be any one selected from cathodic electrochromic reduced state coloring material, cathodic electrochromic oxidized state coloring material and cathodic electrochromic multicolor material, respectively, and the materials of the first electrochromic layer and the second electrochromic layer can be any one selected from anodic electrochromic reduced state coloring material, anodic electrochromic oxidized state coloring material and anodic electrochromic multicolor material, respectively. By combining a specific color changing method, it is possible to convert between different colors. It is possible to match between different types of materials according to the color needs of the terminal product.

[0021] In one embodiment of the present application, the materials of the first electrochromic layer and the second electrochromic layer are not cathodic electrochromic multicolor materials and are not anodic electrochromic multicolor materials at the same time.

[0022] In one embodiment of the present application, neither of the materials of the first electrochromic layer and the second electrochromic layer is a cathodic electrochromic multicolor material, and neither of the materials is an anodic electrochromic multicolor material.

[0023] Because the material selection and color matching of the cathodic electrochromic multicolor material and the anodic electrochromic multicolor material are complicated, when the product needs of the electrochromic device of the terminal product are to be converted between two color states, the cathodic electrochromic reduced state coloring material, the cathodic electrochromic oxidized state coloring material, the anodic electrochromic reduced state coloring material and the anodic electrochromic oxidized state coloring material are preferably selected. In this case, it should be understood that it does not mean to exclude the use of the cathodic electrochromic multicolor material and the anodic electrochromic multicolor material.

[0024] In one embodiment of the present application, the materials of the first electrochromic layer and the second electrochromic layer are both cathodic electrochromic reduced state coloring materials, cathodic electrochromic oxidized state coloring materials, anodic electrochromic reduced state coloring materials, or anodic electrochromic oxidized state coloring materials. The electrochromic device thus obtained is pretreated, and then, by applying a forward voltage, one layer (layer A) of the two electrochromic layers becomes colored and the other layer (layer B) becomes colorless, and by applying a reverse voltage, one layer (layer A) becomes colorless and the other layer (layer B) becomes colored. The color can be converted between two colors.

[0025] In the present application, the materials of the two electrochromic layers may be a cathodic electrochromic reduced state coloring material and a cathodic electrochromic oxidized state coloring material on one side, or an anodic electrochromic reduced state coloring material and an anodic electrochromic oxidized state coloring material on the other side. The color of the electrochromic device thus obtained can be converted between colorless and the color of the two electrochromic layers superimposed on each other.

[0026] In one embodiment of the present application, the materials of the first electrochromic layer and the second electrochromic layer are not the same material. Specifically, for example, when the materials of the two electrochromic layers are both cathodic electrochromic reduced state coloring materials, the materials of the first electrochromic layer and the second electrochromic layer are preferably two materials selected from cathodic electrochromic reduced state coloring materials. If the first electrochromic layer and the second electrochromic layer are the same material, the electrochromic device will not undergo color conversion after applying forward and reverse voltages, so the materials of the first electrochromic layer and the second electrochromic layer in the present application are preferably different materials.

[0027] In one embodiment of the present application, the maximum charge transfer rate per unit area of ​​the first electrochromic layer is 0 to 35 C / cm 2 and does not include 0, for example, 0.05 C / cm 2 , 0.1C / cm 2 , 0.5C / cm 2 , 1C / cm 2 , 2C / cm 2 , 5C / cm 2 , 8C / cm 2 , 10C / cm 2 , 12C / cm 2 , 15C / cm 2 , 18C / cm 2 , 20C / cm 2 , 22C / cm 2 , 25C / cm 2 , 28C / cm 2 , 30C / cm 2 , 32C / cm 2 or 35C / cm 2 The maximum charge transfer rate per unit area of ​​the second electrochromic layer may be 0 to 35 C / cm. 2 and does not include 0, for example, 0.05 C / cm 2 , 0.1C / cm 2 , 0.5C / cm 2 , 1C / cm 2 , 2C / cm 2 , 5C / cm 2 , 8C / cm 2 , 10C / cm 2 , 12C / cm 2 , 15C / cm 2 , 18C / cm 2 , 20C / cm 2 , 22C / cm 2 , 25C / cm 2 , 28C / cm 2 , 30C / cm 2 , 32C / cm 2 or 35C / cm 2 etc. may be used.

[0028] In one embodiment of the present application, the ratio of the maximum charge transfer number per unit area of ​​the first electrochromic layer to the second electrochromic layer is 1:50 to 50:1, for example, 1:50, 1:45, 1:40, 1:35, 1:30, 1:25, 1:20, 1:15, 1:10, 1:8, 1:6, 1:5, 1:3, 1:2, 1:1, 2:1, 3:1, 5:1, 6:1, 8:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1 or 50:1, more preferably 1:10 to 10:1.

[0029] The maximum charge transfer number per unit area of ​​the electrochromic layer is related to the type of material and the thickness of the electrochromic layer. For electrochromic layers with a fixed material, the maximum charge transfer number per unit area increases with increasing thickness. If the thickness of the first electrochromic layer and the second electrochromic layer is too large, the maximum charge transfer number per unit area is too large, and the color change time is long during color change, the color change is not complete, and the color conversion effect is not good. If the thickness of the first electrochromic layer and the second electrochromic layer is too small, the maximum charge transfer number per unit area is too small, the color is shallow, the color change effect is poor, and the service life of the device is short. If the difference between the maximum charge transfer number per unit area between the first electrochromic layer and the second electrochromic layer is too large, the difference between the color depth between the two is too large, which is also likely to cause the color conversion effect to be poor.

[0030] In one embodiment of the present application, the electrolyte layer is a gel electrolyte layer, a liquid electrolyte layer, or a solid electrolyte layer, more preferably a solid electrolyte layer, and further preferably a solid polymer electrolyte layer.

[0031] In one embodiment of the present application, the thickness of the electrolyte layer is 0.1 to 200 μm, and may be, for example, 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 150 μm, 160 μm, 180 μm, or 200 μm.

[0032] In the present application, the type of the electrolyte layer is not particularly limited, and, for example, the solid electrolyte layer may be made of the following materials.

[0033] In one embodiment of the present application, the solid electrolyte layer contains a neutral organic small molecule, the weight percent content of the neutral organic small molecule is 30 wt% or less, for example, 25 wt%, 20 wt%, 15 wt%, 10 wt%, 5 wt%, etc. The molecular weight of the neutral organic small molecule is 3000 or less, for example, 2500, 2000, 1500, 1000, 500, etc.

[0034] In one embodiment of the present application, the solid electrolyte layer comprises a solid electrolyte polymer having covalently linked plasticizing groups.

[0035] In one embodiment of the present application, the solid electrolyte polymer is a copolymer of a monomer or oligomer and an ion-conducting polymer, and the monomer or oligomer has a plasticizing group in a side chain. Further, the constituents of the solid electrolyte layer include a monomer or oligomer segment having a crosslinking group in a side chain.

[0036] The term "further" as used herein means that, in the above-mentioned definition, the constituent components of the solid electrolyte layer preferably contain a copolymer of a monomer or oligomer and an ion-conductive polymer, and further preferably, the copolymer further contains a monomer or oligomer segment having a crosslinking group in the side chain. The following "further" is interpreted in the same way.

[0037] The plasticizing group and the plasticizing group refer to a group that can weaken the interaction between polymers and reduce the polymer crystallinity.

[0038] In one embodiment of the present application, the solid electrolyte polymer is a plasticized linear polymer and an ionically conductive polymer linked by chemical bonds. The glass transition temperature of the plasticized linear polymer is below -20°C. Furthermore, the components of the solid electrolyte layer further include a monomer or polymer having a crosslinking group on a side chain. The monomer or polymer having a crosslinking group on a side chain, the plasticized linear polymer, and the ionically conductive polymer are linked by chemical bonds.

[0039] In one embodiment of the present application, the solid electrolyte polymer is a polymer having a crosslinking group in a side chain and a glass transition temperature below −20° C., and an ionically conductive polymer, which are linked by chemical bonds. Furthermore, the components of the solid electrolyte layer also include a monomer or polymer having a crosslinking group in a side chain. The monomer or polymer having a crosslinking group in a side chain, the plasticized linear polymer, and the ionically conductive polymer are linked by chemical bonds.

[0040] In one embodiment of the present application, the solid electrolyte polymer is a brush-like polymer having a flexible polymer backbone, ion-conducting side chains, and immiscible phase side chains, and further, the components of the solid electrolyte layer include monomers or oligomers having crosslinking groups in their side chains, and the monomers or oligomers having crosslinking groups in their side chains are chemically bonded to the brush-like polymer by block copolymerization.

[0041] The immiscible phase side chains in this application refer to side chains that are significantly different from the properties of other side chains or polymers and cannot be effectively blended, whereas the brush polymers in this application refer to polymers whose main chain is a flexible polymer and which have two types of side chains, one type of side chain used to conduct ions and the other type of side chain that is significantly different from the ion-conducting side chains and cannot be effectively blended. In this application, the introduction of such unblendable side chains reduces the crystallinity of the polymer, making the polymer disordered, and further improves the ion-conducting ability and transparency of the entire polymer.

[0042] In one embodiment of the present application, the ionic transition layer is a flexible solid electrolyte layer. The polymer of the flexible solid electrolyte layer may be selected from the following four types of polymers:

[0043] In the structural formulas of the following four types of polymers, x, y, and z are each independently selected from integers equal to or greater than 0. The rectangles in the formulas represent polymer blocks with ion-conducting properties (ion-conductive polymer blocks), and the ovals represent monomers or polymers with side chains called PR (plasticizing group), CL (crosslinking group), NM (non-mixed phase group), or IC (ion-conductive group).

[0044] [ka]

[0045] A block copolymer (represented by PEGPRCL) formed by copolymerization of a polymer block y having ion-conducting properties (e.g., polyethylene glycol, or other materials reported in the literature), a monomer or polymer block x having a plasticizing group (PR) in the side chain, and a monomer or polymer block z having a crosslinking group (CL) in the side chain, or a block copolymer (represented by PEGPR) formed by copolymerization of a polymer block y having ion-conducting properties (e.g., polyethylene glycol, or other materials reported in the literature) and a monomer or polymer block x having a plasticizing group (PR) in the side chain.

[0046] [ka]

[0047] A block copolymer (represented by PEGSPCL) formed by copolymerization of a polymer block y having ion-conducting properties (e.g., polyethylene glycol, or other materials reported in the literature), a linear plasticized polymer (SP) block x having a glass transition temperature below -20°C (e.g., polyethylene, polybutene, polyisobutene, siloxane, or other materials reported in the literature), and a monomer or polymer block z having a crosslinking group (CL) in the side chain. Alternatively, a block copolymer (represented by PEGSP) formed by chemically linking a polymer block y having ion-conducting properties (e.g., polyethylene glycol, or other materials reported in the literature) and a linear plasticized polymer (SP) block x having a glass transition temperature below -20°C (e.g., polyethylene, polybutene, polyisobutene, siloxane, or other materials reported in the literature).

[0048] [ka]

[0049] A block copolymer (represented by PEGSP-PRCL) in which an ion-conducting polymer block y (e.g., polyethylene glycol, or other materials reported in the literature) and a plasticizing polymer (SP-PR) block x having plasticizing side chains are linked by a chemical reaction and then copolymerized with a monomer or oligomer (CL) block z having a crosslinking group in the side chain, or a block copolymer (represented by PEGSP-PR) in which an ion-conducting polymer block y (e.g., polyethylene glycol, or other materials reported in the literature) and a plasticizing polymer (SP-PR) block x having plasticizing side chains are linked by a chemical reaction.

[0050] [ka]

[0051] Comb block copolymers (ICNMCL) formed by chemically linking flexible polymer blocks x having ion-conducting oligomers or polymers (e.g., polyethylene glycol or other materials reported in the literature) with flexible polymer blocks y having side chains that do not blend with ion-conducting polymers (e.g., alkyl, aromatic, or mixed alkyl and aromatic side chains) and then copolymerizing them with monomer or oligomer (CL) blocks z having crosslinking groups in the side chains. Alternatively, comb block copolymers (ICNM) formed by chemically linking flexible polymer blocks x having ion-conducting oligomers or polymers (e.g., polyethylene glycol or other materials reported in the literature) with flexible polymer blocks y having side chains that do not blend with ion-conducting polymers (e.g., alkyl, aromatic, or mixed alkyl and aromatic side chains).

[0052] The polymeric material used in the ionic transition layer needs to be further blended with a certain amount of organic salt and / or inorganic salt to form an electrolyte precursor. The inorganic salt includes but is not limited to lithium salt, sodium salt, potassium salt, magnesium salt, calcium salt, aluminum salt, and the organic salt includes but is not limited to ionic liquid, such as EMITFSI, EMIOTF. An initiator may be introduced to blend to form an electrolyte precursor. The electrolyte precursor can be crosslinked by heating, photoinitiation, or other methods to form the final all-solid electrolyte.

[0053] As used herein, plasticizing groups (PR) include, but are not limited to, the following structures:

[0054] [ka]

[0055] The bridging group (CL) includes, but is not limited to, the following structures:

[0056] [ka]

[0057] The backbone of the comb block copolymer includes, but is not limited to, the following structure:

[0058] [ka]

[0059] The ion-conducting group (IC) includes, but is not limited to, the following structures:

[0060] [ka]

[0061] In one embodiment of the present application, the materials of the first base and the second base are each independently glass or a flexible material, preferably a transparent material, including but not limited to PET (polyethylene terephthalate), cycloolefin copolymer, cellulose triacetate, etc.

[0062] In a second aspect, the present application provides a method for changing the colour of an electrochromic device as described in the first aspect, comprising: (1) applying a second voltage in a second direction opposite to the first direction to a pre-treated electrochromic device, causing the first electrochromic layer to change from a third color to the first color and the second electrochromic layer to change from the second color to a fourth color, the pre-treatment comprising applying a first voltage in a first direction to the electrochromic device, causing the first electrochromic layer to change from the first color to a third color and maintaining the second electrochromic layer at the second color; (2) applying a third voltage in a first direction to the pretreated electrochromic device, thereby causing the first electrochromic layer to change from the first color to a third color and causing the second electrochromic layer to change from a fourth color to a second color. A method for changing color is provided.

[0063] In this application, the function of the pretreatment is as follows: By gaining or losing electrons, the first electrochromic layer undergoes a reversible oxidation / reduction reaction to change its color. At the same time, the second electrochromic layer undergoes a non-Faradic reaction and some irreversible electrochemical reaction, and the generated charge balances the charge of the electrochromic device, and the second electrochromic layer does not undergo a Faradaic reaction related to color change, so the color of the second electrochromic layer remains the same. After being pretreated, the electrochromic device can be converted between different colors by applying a voltage with the opposite direction in a cycle. And the pretreatment step is only performed when the electrochromic device is used for the first time, and does not need to be performed during subsequent uses. The electrochromic devices in the prior art do not perform a pretreatment step when changing color. In the present application, by arranging a structure in which the two electrochromic layers are both anodic electrochromic materials or cathodic electrochromic materials, and combining the above-mentioned specific color change method, the electrochromic device of the present application can realize conversion between different colors and expand the selection range of electrochromic materials.

[0064] In practical application, the pretreatment may be performed by the manufacturer of the electrochromic device, or may be performed by the user when using it for the first time, or may be selected by those skilled in the art according to practical needs.

[0065] In addition, the critical voltage V1 at which the first electrochromic layer is transformed from the first color to the third color in the pretreatment step of the present application is higher than the critical voltage V1' at which the first electrochromic layer is transformed from the first color to the third color in step (2), so that if the voltage V1' is applied to the electrochromic device of the present application according to the conventional method of using the electrochromic device, the pretreatment cannot be performed on the electrochromic device, and the color transformation cannot be realized. Wherein, V1 may be measured by gradually increasing the voltage and observing the reversibility of the color transformation of the first electrochromic layer, or may be measured from the cyclic voltammetry graph of the electrochromic device.

[0066] In one embodiment of the present application, the absolute value of the first voltage is equal to or greater than V1, where V1 is a critical voltage that causes an irreversible electrochemical reaction in the second electrochromic layer.

[0067] In the pretreatment step of the present application, a high voltage (greater than or equal to V1 and less than V2) is used to cause an irreversible electrochemical reaction in the second electrochromic layer, where V2 is the voltage at which the electrochromic device is destroyed. If the first voltage is greater than V2, some of the materials in the electrochromic layer will undergo irreversible transformation, resulting in structural damage, which will degrade the quality of the electrochromic device and even destroy it.

[0068] In one embodiment of the present application, the absolute value of the third voltage is smaller than the absolute value of the first voltage. During the color conversion process, the third voltage only needs to generate a reversible electrochemical reaction in the material of the electrochromic layer, and does not need to generate an irreversible electrochemical reaction. Therefore, the third voltage is smaller than the voltage required for the pretreatment step.

[0069] In a third aspect, the present application provides an electronic terminal comprising an electrochromic device as described in the first aspect.

[0070] The electronic terminal may be a consumer electronic product, a door or window, a cabinet, an electronic label, a wearable device, an intelligent eyeglasses, a phototherapy device, etc. For example, when the electrochromic device is applied to the electronic terminal, it is disposed at any required location such as the surface or inside of the terminal, and according to the specific application scene, it can achieve the effects of diversifying the appearance, shielding privacy, displaying the status, distinguishing information, adjusting the environmental brightness, filtering / transmitting light rays of different predetermined wavelengths, etc. Effect of the Invention

[0071] Compared with the prior art, the present application has the following beneficial effects:

[0072] The electrochromic device of the present application uses cathodic electrochromic materials or anodic electrochromic materials for the two electrochromic layers, and can be transformed between different colors by combining a specific color changing method, so that the materials of the two electrochromic layers do not need to be limited to the combination of cathodic electrochromic materials and anodic electrochromic materials, and the selection range of electrochromic materials can be expanded. This electrochromic device is easy to be widely used for more color interconversion, and can meet the needs of multi-color display and personalization. [Brief description of the drawings]

[0073] [Figure 1] FIG. 2 is a structural schematic diagram of an electrochromic device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0074] The technical solution of the present application will be further described below in conjunction with the drawings and specific embodiments. Those skilled in the art should understand that the specific embodiments are only for understanding the present application, and should not be regarded as specifically limiting the present application.

[0075] In the examples of the present application, the method for preparing the electrolyte polymer component of the electrolyte layer is as follows.

[0076] The method for preparing polymer A (a type of solid electrolyte polymer belonging to PEGPRCL) is as follows.

[0077] [ka]

[0078] Bromoisobutyric acid-terminated PEG (polyethylene glycol), acrylate with a plasticizing group, a crosslinking group with two acrylic acids, a monovalent copper catalyst, and PMDETA (N,N,N',N'',N''-pentamethyldiethylenetriamine) ligand were added to a suitable organic solvent. The mixed solution (the mixture without the addition of the solvent may be used as it is in the manufacture of devices as an electrolyte precursor) was reacted at 100°C for 12 hours, filtered through diatomaceous earth, and the solvent was removed under reduced pressure to obtain polymer A.

[0079] The preparation method of polymer B (a type of solid electrolyte polymer belonging to PEGPR) is as follows.

[0080] [ka]

[0081] PEG diamine (polyethylene glycol diamine) and phthaloyl chloride were added to a suitable organic solvent. Polymer electrolyte was obtained by direct polymerization under alkaline conditions (the mixture without adding solvent may be directly used as an electrolyte precursor for device fabrication). After washing with water, separation and drying, the solvent was removed to obtain polymer B.

[0082] The preparation method of polymer C (a type of solid electrolyte polymer belonging to PEGSPCL) is as follows.

[0083] [ka]

[0084] PEG (polyethylene glycol), polysiloxane diamine, tetramine as a crosslinker, and CDI (carbonyldiimidazole) as a condensing agent were added to a suitable organic solvent (the mixture without the addition of solvent may be used as it is for device fabrication as an electrolyte precursor). The mixture was reacted at 90°C to obtain a polymer. After washing with water, separation and drying, the solvent was removed to obtain polymer C.

[0085] The preparation method of polymer D (a type of solid electrolyte polymer belonging to PEGSP) is as follows.

[0086] [ka]

[0087] PEG (polyethylene glycol), polysiloxane diamine, and condensing agent CDI (carbonyldiimidazole) were added to a suitable organic solvent (the mixture without the addition of solvent may be used as it is for device fabrication as an electrolyte precursor). The mixture was reacted at 120°C to obtain a polymer. After washing with water, separation and drying, the solvent was removed to obtain polymer D.

[0088] The preparation method of polymer E (a type of solid electrolyte polymer belonging to PEGSP-PRCL) is as follows.

[0089] [ka]

[0090] PEG (polyethylene glycol), polysiloxane diol, tetraol as a crosslinker, and CDI (carbonyldiimidazole) as a condensing agent were added to a suitable organic solvent (the mixture without the addition of solvent may be used as it is for device fabrication as an electrolyte precursor). The mixture was reacted at 100°C to obtain a polymer. After washing with water, separation and drying, the solvent was removed to obtain polymer E.

[0091] The preparation method of polymer F (a type of solid electrolyte polymer belonging to PEGSP-PR) is as follows.

[0092] [ka]

[0093] PEG (polyethylene glycol), polysiloxane diol, and condensing agent CDI (carbonyldiimidazole) were added to a suitable organic solvent (the mixture without the addition of solvent may be used as it is in the manufacture of devices as an electrolyte precursor). The mixture was reacted at 100°C to obtain a polymer. After washing with water, separation and drying, the solvent was removed to obtain polymer F.

[0094] The preparation method of polymer G (a type of solid electrolyte polymer belonging to ICNMCL) is as follows.

[0095] [ka]

[0096] Acrylic acid alkyl ester, polyethylene glycol acrylate, ethylene glycol diacrylate, AIBN (azobisisobutylcyanide) were added to a suitable organic solvent (the mixture without the addition of solvent may be used as it is for device fabrication as an electrolyte precursor). The mixture was reacted by irradiation to obtain a polymer. After washing with water, separation and drying, the solvent was removed to obtain polymer G.

[0097] The preparation method of polymer H (a type of solid electrolyte polymer belonging to ICNM) is as follows.

[0098] [ka]

[0099] Acrylic acid alkyl ester, polyethylene glycol acrylate, and AIBN (azobisisobutylcyanide) were added to a suitable organic solvent (the mixture without the addition of solvent may be used as it is in the manufacture of devices as an electrolyte precursor). The mixture was reacted by irradiation to obtain a polymer. After washing with water, separation and drying, the solvent was removed to obtain polymer H.

[0100] In the embodiments of the present application, when the potential of the first electrochromic layer 3 is higher than the potential of the second electrochromic layer 5, the voltage direction is called a forward direction, and when the potential of the first electrochromic layer 3 is lower than the potential of the second electrochromic layer 5, the voltage direction is called a reverse direction.

[0101] In the examples of the present application, the method for measuring the maximum charge transfer number per unit area of ​​the electrochromic layer is as follows.

[0102] 1. The electrochromic layer to be measured was connected to a three-electrode system with Ag / AgCl as the working electrode, Ag / AgCl as the reference electrode, and Pt as the counter electrode. The electrolyte solution was 50% lithium perchlorate in propylene carbonate.

[0103] 2. Cyclic voltammetry tests were performed on the above three-electrode system using an electrochemical workstation. The starting and ending voltages were 0V, the scan rate was 0.05V / s, the number of scan cycles was 6, and the sensitivity was e^(-2). The maximum and minimum voltages of the scan can be appropriately adjusted according to the material of the electrochromic layer so that a completely symmetrical redox peak appears in the electrochromic layer being tested during scanning.

[0104] 3. The area of ​​the cyclic voltammetry graph was integrated, and the area integral result was denoted as S.

[0105] 4. The maximum number of charge transfers per unit area, Q = S / (2 × V × A), was calculated.

[0106] Wherein, V is the scanning speed when scanning the cyclic voltammetry graph, and A is the area of ​​the electrochromic layer immersed in the electrolyte solution.

[0107] Example 1

[0108] This embodiment provides an electrochromic device, the structural schematic diagram of which is shown in Figure 1, which includes a first base 1, a first transparent conductive layer 2, a first electrochromic layer 3, an electrolyte layer 4, a second electrochromic layer 5, a second transparent conductive layer 6 and a second base 7, which are stacked in order. Among them, the materials of the first electrochromic layer 3 and the second electrochromic layer 5 are both anodic electrochromic reduced state coloring materials.

[0109] The method for producing the electrochromic device is as follows.

[0110] 1) Production of the first electrochromic layer 3

[0111] 300 mg of poly-2-[(2-ethylhexyloxy)methyl]3,4-thieno-1,4-dioxane was dissolved in 10 mL of o-xylene and stirred with a magnetic stirrer for 10 h, after which the resulting solution was dropped onto an ITO layer (first transparent conductive layer 2) plated on a glass substrate (first base 1). After spin-coating and drying, a first electrochromic layer 3 (thickness 200 nm) was formed. The maximum charge transfer number per unit area of ​​the first electrochromic layer 3 was tested (3.3 C / cm 2 ).

[0112] 2) Production of the second electrochromic layer 5

[0113] 400 mg of poly(3-hexylthiophene) (P3HT) was dissolved in 10 mL of chloroform and stirred with a magnetic stirrer for 10 h. The resulting solution was then dropped onto the ITO layer (second transparent conductive layer 6) plated on the glass substrate (second base 7). After spin-coating and drying, a second electrochromic layer 5 (300 nm thick) was formed. The maximum charge transfer number per unit area of ​​the second electrochromic layer 5 was tested (4.2 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 0.79:1.

[0114] 3) Assembly of electrochromic devices

[0115] 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer H, and 0.1 wt% azobisisobutyronitrile were mixed and applied to the first electrochromic layer 3 to form an electrolyte coating. Then, the second electrochromic layer 5 (together with the ITO layer and the glass substrate) was offset and covered onto the electrolyte coating. The electrolyte coating was cured by UV light to form an electrolyte layer 4 (50 μm thick), and an electrochromic device was obtained.

[0116] 4) Electrode placement

[0117] The offset exposed first electrochromic layer 3 and second electrochromic layer 5 materials were washed with acetone to expose the first transparent conductive layer 2 and second transparent conductive layer 6. Copper adhesive was applied to the conductive layers as positive and negative electrodes.

[0118] This embodiment further provides a method for changing the color of the electrochromic device described above, comprising the steps of:

[0119] (1) Pretreatment by applying forward voltage

[0120] The first electrochromic layer 3 was connected to the positive electrode of a power source, the second electrochromic layer 5 was connected to the negative electrode of a power source, and a forward voltage (1.8 V) was applied to the device, whereby the first electrochromic layer 3 was oxidized from blue-purple to colorless, and the second electrochromic layer 5 still maintained red. In the present application, the timing of the pretreatment is not particularly limited and may be performed at any timing before the electrochromic device performs the first conversion between different colors, or after the step of arranging the electrodes in the manufacturing method.

[0121] (2) Conversion between different colors

[0122] By applying a reverse voltage (-1.0 V) to the electrochromic device, the first electrochromic layer 3 was reduced from colorless to blue-purple and the second electrochromic layer 5 was oxidized from red to colorless. By applying a forward voltage (0 V) to the electrochromic device, the first electrochromic layer 3 was oxidized from blue-purple to colorless and the second electrochromic layer 5 was reduced from colorless to red. By cycling reverse voltages (-1.0 V) and forward voltages (0 V) to the device, the color of the device transformed between blue-purple and red.

[0123] The electrochromic device according to the present embodiment may be used in terminal products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices. For example, it may be used in phototherapy devices. The phototherapy devices may be glasses, helmets, displays, etc. When manufactured as a lens or display screen, it can be used to filter / transmit light rays of different predetermined wavelengths and allow light rays of a specific wavelength to enter the user's eyes, thereby achieving effects such as time difference adjustment, improvement of sleep quality, relief of fatigue, and mood relaxation.

[0124] Example 2

[0125] This embodiment provides an electrochromic device, the structural schematic diagram of which is shown in Figure 1, which includes a first base 1, a first transparent conductive layer 2, a first electrochromic layer 3, an electrolyte layer 4, a second electrochromic layer 5, a second transparent conductive layer 6 and a second base 7, which are stacked in order. Among them, the materials of the first electrochromic layer 3 and the second electrochromic layer 5 are both cathodic electrochromic oxidation state coloring materials.

[0126] The method for producing the electrochromic device is as follows.

[0127] 1) Production of the first electrochromic layer 3

[0128] 80 mg of potassium ferricyanide was weighed and dissolved in 25 mL of deionized water, and 60 mg of nickel acetate was weighed and dissolved in 25 mL of deionized water, and then stirred uniformly. The potassium ferricyanide solution was added to the nickel acetate solution to form a precipitate, and the precipitate was washed three times with water and ethanol, respectively. The precipitate was dried, weighed out to 50 mg, and dissolved again in 10 mL of deionized water to form a solution. The resulting solution was then dropped onto an ITO layer (first transparent conductive layer 2) plated on a glass substrate (first base 1). After spin-coating and drying, a first electrochromic layer 3 (Prussian blue system, 200 nm thick) was formed. The maximum charge transfer number per unit area of ​​the first electrochromic layer 3 was tested (8.9 C / cm 2 ).

[0129] 2) Production of the second electrochromic layer 5

[0130] First, 50 mL of potassium chloride solution with a concentration of 35 mmol / mL was prepared, and nitrogen gas was introduced to remove oxygen. Then, 25 mL was measured and tetrapotassium hexacyanoruthenate salt hydrate was dissolved in this solution. The remaining 25 mL of potassium chloride oxygen-removed solution was prepared as a 1 mmol / mL iron chloride solution. The two obtained solutions were mixed with a high-speed magnetic stirrer to obtain a colloidal suspension solution of bright purple ruthenium violet. Then, the obtained colloidal solution was adjusted to PH=2 with hydrochloric acid. Finally, 1 mL of 1 mmol / mL ruthenium chloride solution was added under the condition of introducing nitrogen gas. Then, the obtained solution was transferred to an electrochemical pool. Using ITO (second transparent conductive layer 6) on a glass base (second base 7) as an electrode, it was cycled between -0.2 V and 0.6 V by cyclic voltammetry. A thin film of ruthenium violet was electrochemically deposited on the electrode to form a second electrochromic layer 5 (thickness 250 nm). The maximum charge transfer rate per unit area of ​​the second electrochromic layer 5 was tested (10.2 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 0.87:1.

[0131] 3) Assembly of electrochromic devices

[0132] 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer G, 40%, 40 mmol / mL KCl solution and 0.1 wt% azobisisobutyronitrile were mixed and applied to the first electrochromic layer 3 to form an electrolyte coating. Then, the second electrochromic layer 5 (together with the ITO layer and the glass substrate) was shifted and covered on the electrolyte coating. The electrolyte coating was cured by ultraviolet light to form an electrolyte layer 4 (thickness 10 μm) to obtain an electrochromic device.

[0133] 4) Electrode placement

[0134] The offset exposed first electrochromic layer 3 and second electrochromic layer 5 materials were washed with acetone to expose the first transparent conductive layer 2 and second transparent conductive layer 6. Copper adhesive was applied to the conductive layers as positive and negative electrodes.

[0135] This embodiment further provides a method for changing the color of the electrochromic device described above, comprising the steps of:

[0136] (1) Pre-processing by applying reverse voltage

[0137] By applying a reverse voltage (-1.2V) to the device, the first electrochromic layer 3 was reduced from dark blue to colorless, while the second electrochromic layer 5 still maintained a purple color. In the present application, the timing of the pretreatment is not particularly limited, and may be performed when the electrochromic device first transforms between different colors, or may be performed immediately after the electrode arrangement step in the manufacturing method of the electrochromic device.

[0138] (2) Conversion between different colors

[0139] By applying a forward voltage (0.5V) to the electrochromic device, the first electrochromic layer 3 was oxidized from colorless to dark blue and the second electrochromic layer 5 was reduced from purple to colorless. By applying a reverse voltage (-0.5V) to the electrochromic device, the first electrochromic layer 3 was reduced from dark blue to colorless and the second electrochromic layer 5 was oxidized from colorless to purple. By cycling forward voltage (0.5V) and reverse voltage (-0.5V) to the device, the color of the device transformed between dark blue and purple.

[0140] The electrochromic device according to the present embodiment may be used in terminal products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, phototherapy devices, etc. For example, it may be used in consumer electronic products. The consumer electronic products may be mobile phones, tablets, personal computers, watches, etc. It may be applied to the product housing or display or any other part to provide the consumer electronic products with rich appearance effects, and may further be used to realize effects such as displaying different status information according to different color states.

[0141] Example 3

[0142] This embodiment provides an electrochromic device, the structural schematic diagram of which is shown in Figure 1, which includes a first base 1, a first transparent conductive layer 2, a first electrochromic layer 3, an electrolyte layer 4, a second electrochromic layer 5, a second transparent conductive layer 6 and a second base 7, which are stacked in order. Among them, the materials of the first electrochromic layer 3 and the second electrochromic layer 5 are both cathodic electrochromic reduced state coloring materials.

[0143] The method for producing the electrochromic device is as follows.

[0144] 1) Production of the first electrochromic layer 3

[0145] 100 mg of tungsten powder with a purity of 99.9% was dissolved in 10 mL of 30 wt% hydrogen peroxide solution and stirred at room temperature for 4 h. After stirring, the lower layer precipitate was filtered, and anhydrous ethanol and glacial acetic acid were added, followed by continuous stirring for 4 h. The resulting solution was then dropped onto an ITO layer (first transparent conductive layer 2) plated on a glass substrate (first base 1). After spin-coating and drying at a high temperature of 450 °C, a first electrochromic layer 3 (WO3, 10 nm thick) was formed. The maximum charge transfer number per unit area of ​​the first electrochromic layer 3 was tested (7 C / cm 2 ).

[0146] 2) Production of the second electrochromic layer 5

[0147] 130 mg of Nb2O5 powder was dissolved in a mixed solution of 2.5 mL of glacial acetic acid and 12.5 mL of butanol, and after stirring with a magnetic stirrer for 10 h, the obtained solution was dropped onto the ITO layer (second transparent conductive layer 6) plated on the glass substrate (second base 7). After spin-coating and drying at a high temperature of 700 °C, a second electrochromic layer 5 (thickness 50 nm) was formed. The maximum charge transfer number per unit area of ​​the second electrochromic layer 5 was tested (13 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 0.54:1.

[0148] 3) Assembly of electrochromic devices

[0149] 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer C, and 0.1 wt% carbonyldiimidazole were mixed and applied to the first electrochromic layer 3 to form an electrolyte coating. Then, the second electrochromic layer 5 (together with the ITO layer and the glass substrate) was shifted and covered onto the electrolyte coating. The electrolyte coating was thermally cured at 90° C. to form an electrolyte layer 4 (thickness 80 μm), and an electrochromic device was obtained.

[0150] 4) Electrode placement

[0151] The offset exposed first electrochromic layer 3 and second electrochromic layer 5 materials were washed with acetone to expose the first transparent conductive layer 2 and second transparent conductive layer 6. Copper adhesive was applied to the conductive layers as positive and negative electrodes.

[0152] This embodiment further provides a method for changing the color of the electrochromic device described above, comprising the steps of:

[0153] (1) Pre-processing by applying reverse voltage

[0154] By applying a reverse voltage (-3.0V) to the device, the first electrochromic layer 3 was reduced from colorless to blue, and the second electrochromic layer 5 remained colorless. In the present application, the timing of the pretreatment is not particularly limited, and may be performed when the electrochromic device first transforms between different colors, or may be performed immediately after the electrode arrangement step in the manufacturing method of the electrochromic device.

[0155] (2) Conversion between different colors

[0156] By applying a forward voltage (1.5V) to the electrochromic device, the first electrochromic layer 3 was oxidized from blue to colorless and the second electrochromic layer 5 was reduced from colorless to light gray. By applying a reverse voltage (-1.5V) to the electrochromic device, the first electrochromic layer 3 was reduced from colorless to blue and the second electrochromic layer 5 was oxidized from light gray to colorless. By cycling forward voltage (1.5V) and reverse voltage (-1.5V) to the device, the color of the device transformed between light gray and blue.

[0157] The electrochromic device according to the present embodiment may be used in terminal products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices. For example, it may be applied to doors and windows, or to the glass of doors and windows. By adjusting the color and transmittance of the glass according to the needs of the user, it is possible to achieve effects such as privacy shielding, adjustment of environmental brightness, and adjustment of temperature.

[0158] Example 4

[0159] This embodiment provides an electrochromic device, which is different from the first embodiment in the following points: the materials of the first electrochromic layer 3 and the second electrochromic layer 5 are both anodic electrochromic oxidation state coloring materials, and the constituent material of the electrolyte layer 4 is replaced by polymer F.

[0160] The material of the first electrochromic layer 3 is NiO, and a film is formed by sputtering reaction using Ni as a metal target material, with a thickness of 90 nm and a maximum charge transfer rate per unit area of ​​18 C / cm. 2 The material of the second electrochromic layer 5 is IrO2, and a film is formed by a sputtering reaction using Ir as a metal target material, with a thickness of 125 nm and a maximum charge transfer rate per unit area of ​​25 C / cm. 2 The ratio of the maximum charge transfer number per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 0.66:1. The electrolyte layer 4 is formed by mixing 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer F, and 0.1 wt% carbonyldiimidazole, and thermally curing it at 100°C, and has a thickness of 50 μm.

[0161] This embodiment further provides a method for changing the color of the electrochromic device described above, comprising the steps of:

[0162] (1) Pretreatment by applying forward voltage

[0163] By applying a forward voltage (3V) to the device, the first electrochromic layer 3 was oxidized from colorless to dark brown, while the second electrochromic layer 5 remained colorless. In the present application, the timing of the pretreatment is not particularly limited, and may be performed when the electrochromic device first transforms between different colors, or may be performed immediately after the electrode arrangement step in the manufacturing method of the electrochromic device.

[0164] (2) Conversion between different colors

[0165] By applying a reverse voltage (-1.8V) to the electrochromic device, the first electrochromic layer 3 was reduced from dark brown to colorless and the second electrochromic layer 5 was oxidized from colorless to blue-black. By applying a forward voltage (1.8V) to the electrochromic device, the first electrochromic layer 3 was oxidized from colorless to dark brown and the second electrochromic layer 5 was reduced from blue-black to colorless. By cycling reverse voltages (-1.8V) and forward voltages (1.8V) to the device, the color of the device transformed between blue-black and dark brown.

[0166] The electrochromic device according to the present embodiment may be used in terminal products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices. For example, it may be applied to a cabinet, or to the surface or glass of a cabinet. The diversification of appearance can achieve effects such as privacy shielding and adjustment of the internal temperature of the cabinet.

[0167] Example 5

[0168] This example provides an electrochromic device, which is different from Example 1 in the following points: The amount of poly-2-[(2-ethylhexyloxy)methyl]3,4-thieno-1,4-dioxane weighed in the preparation of the first electrochromic layer 3 is 600 mg, the spin-coated thickness is 800 nm, and the maximum charge transfer rate per unit area is 12.2 C / cm 2 The weight of poly(3-hexylthiophene) (P3HT) used in producing the second electrochromic layer 5 was 50 mg, the spin-coated thickness was 12 nm, and the maximum charge transfer rate per unit area was 0.25 C / cm 2The ratio of the maximum charge transfer number per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 48.8:1. The electrolyte layer 4 is formed by replacing the constituent raw materials with polymer B, mixing 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer B and 0.1 wt% and 85% potassium hydroxide for 12 h, and has a thickness of 50 μm.

[0169] The electrochromic device of this example was pretreated by applying a forward voltage (1.8 V), and then cycled through reverse voltage (-1.0 V) and forward voltage (0.4 V), allowing the color of the device to change between blue-purple and red.

[0170] The electrochromic device according to the present embodiment may be used in terminal products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, phototherapy devices, etc. For example, it may be applied to a wearable device, or to the housing or display area of ​​the wearable device, to diversify the appearance, filter light, and achieve other effects.

[0171] Example 6

[0172] This embodiment provides an electrochromic device, which is different from the first embodiment in the following points: the material of the first electrochromic layer 3 is a cathodic electrochromic reduced state coloring material, the material of the second electrochromic layer 5 is a cathodic electrochromic oxidized state coloring material, and the constituent material of the electrolyte layer 4 is replaced by polymer A.

[0173] The material of the first electrochromic layer 3 is WO3, the preparation method is as in Example 3, the thickness is 50 nm, and the maximum charge transfer rate per unit area is 20 C / cm 2 The material of the second electrochromic layer 5 is ruthenium violet, the preparation method is as in Example 2, the thickness is 250 nm, and the maximum charge transfer rate per unit area is 10.2 C / cm2 The ratio of the maximum charge transfer number per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 1.96:1. The electrolyte layer 4 is formed by mixing 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer A, 0.05 wt% cuprous chloride, and 0.1 wt% N,N,N',N'',N''-pentamethyldiethylenetriamine, and thermally curing it at 100°C, and has a thickness of 150 μm.

[0174] The electrochromic device of this embodiment is pretreated by applying a reverse voltage (-3 V) and then cycled through forward voltage (1.2 V) and reverse voltage (-1.5 V), allowing the color of the device to be converted between colorless and superimposed colors (blue and purple).

[0175] The electrochromic device according to the present embodiment may be used in terminal products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, phototherapy devices, etc. For example, when applied to electronic labels, it can achieve the effects of status indication and information distinction.

[0176] Example 7

[0177] This embodiment provides an electrochromic device, which is different from the first embodiment in the following points: the material of the first electrochromic layer 3 is an anodic electrochromic reduced state coloring material, the material of the second electrochromic layer 5 is an anodic electrochromic oxidized state coloring material, and the constituent material of the electrolyte layer is replaced by polymer E.

[0178] The material of the first electrochromic layer 3 is poly-2-[(2-ethylhexyloxy)methyl]3,4-thiophene, the preparation method of which is referred to Example 1, the thickness is 200 nm, and the maximum charge transfer rate per unit area is 3.3 C / cm 2The material of the second electrochromic layer 5 is NiO, the preparation method is as in Example 4, the thickness is 180 nm, and the maximum charge transfer rate per unit area is 32 C / cm 2 The ratio of the maximum charge transfer number per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 1:10. The electrolyte layer 4 is formed by mixing 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer E, and 0.1 wt% carbonyldiazene, and thermally curing it at 100°C, and has a thickness of 30 μm.

[0179] The electrochromic device of this example was pretreated by applying a forward voltage (1.8 V) and then cycled through reverse voltage (-1.0 V) and forward voltage (1 V), allowing the color of the device to be converted between colorless and superimposed colors (off black and blue-purple).

[0180] The electrochromic device according to this embodiment may be used in end products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices.

[0181] Example 8

[0182] This example provides an electrochromic device, which is different from Example 2 in the following points: The amount of potassium ferricyanide weighed during the preparation of the first electrochromic layer 3 is 160 mg, the spin-coated thickness is 400 nm, and the maximum charge transfer rate per unit area is 16 C / cm 2 the thickness of the second electrochromic layer 5 is 250 nm, and the maximum charge transfer rate per unit area is 10.2 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 1.57:1.

[0183] The electrochromic device of this embodiment can be pretreated by applying a reverse voltage (-1.2V) and then cycled with a forward voltage (0.5V) and a reverse voltage (-0.5V) to change the color of the device between dark blue and purple. The electrochromic device of this embodiment can be used in terminal products such as consumer electronics, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices.

[0184] Example 9

[0185] This example provides an electrochromic device, which is different from Example 3 in the following respects: the thickness of the first electrochromic layer 3 is 75 nm, and the maximum charge transfer rate per unit area is 30 C / cm 2 the thickness of the second electrochromic layer 5 is 20 nm, and the maximum charge transfer rate per unit area is 3 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 10:1.

[0186] The electrochromic device of this embodiment can be pretreated by applying a reverse voltage (-3V) and then cycled with a forward voltage (1.5V) and a reverse voltage (-1.5V) to change the color of the device between light gray and blue. The electrochromic device of this embodiment can be used in terminal products such as consumer electronics, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices.

[0187] Example 10

[0188] This embodiment provides an electrochromic device, the structural schematic diagram of which is shown in Figure 1, which includes a first base 1, a first transparent conductive layer 2, a first electrochromic layer 3, an electrolyte layer 4, a second electrochromic layer 5, a second transparent conductive layer 6 and a second base 7, which are stacked in order. Among them, the materials of the first electrochromic layer 3 and the second electrochromic layer 5 are both anodic electrochromic polychromatic materials.

[0189] The method for producing the electrochromic device is as follows.

[0190] 1) Production of the first electrochromic layer 3

[0191] The constant current method was used to measure 10 μA / cm in a 1 mol / L sulfuric acid solution. 2 Aniline with a concentration of 0.1 mol / L was deposited for 30 min at a current density of 1000 s to form a first electrochromic layer 3 (polyaniline thin film, thickness 280 nm) on the ITO layer plated on the glass substrate. The maximum charge transfer rate per unit area of ​​the first electrochromic layer 3 was tested (20 C / cm 2 ).

[0192] 2) Production of the second electrochromic layer 5

[0193] 300 mg of V2O5 sheet crystals were crushed and then placed in a crucible and heated in a muffle furnace at 800°C to completely dissolve into a fluid colloidal solution. After keeping the temperature for 5 minutes, the crystals were placed in a colloid bucket, and 20 mL of deionized water was added and stirred uniformly to obtain a V2O5 colloidal solution. The resulting solution was dropped onto the ITO layer plated on the glass substrate. A second electrochromic layer 5 (thickness 350 nm) was formed by spin coating. The maximum charge transfer rate per unit area of ​​the second electrochromic layer 5 was tested (35 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 0.57:1.

[0194] 3) Assembly of electrochromic devices

[0195] 10 wt% lithium perchlorate, 89.9 wt% precursor of polymer D, and 0.1 wt% carbonyldiimidazole were mixed and applied to the first electrochromic layer 3 to form an electrolyte coating. Then, the second electrochromic layer 5 (together with the ITO layer and the glass substrate) was offset and covered onto the electrolyte coating. The electrolyte coating was thermally cured at 120°C to form an electrolyte layer 4 (thickness 60 μm), and an electrochromic device was obtained.

[0196] 4) Electrode placement

[0197] The offset exposed first electrochromic layer 3 and second electrochromic layer 5 materials were washed with acetone to expose the first transparent conductive layer 2 and second transparent conductive layer 6. Copper adhesive was applied to the conductive layers as positive and negative electrodes.

[0198] This embodiment further provides a method for changing the color of the electrochromic device described above, comprising the steps of:

[0199] (1) Pretreatment by applying forward voltage

[0200] By applying a forward voltage (2.5V) to the device, the first electrochromic layer 3 was oxidized from green to dark blue, and the second electrochromic layer 5 still maintained yellow. In the present application, the timing of the pretreatment is not particularly limited, and may be performed when the electrochromic device first transforms between different colors, or may be performed immediately after the electrode arrangement step in the manufacturing method of the electrochromic device.

[0201] (2) Conversion between different colors

[0202] By applying a reverse voltage (-1.0V) to the electrochromic device, the first electrochromic layer 3 was reduced from dark blue to green, and the second electrochromic layer 5 was oxidized from yellow to gray-black. By applying a forward voltage (1.2V) to the electrochromic device, the first electrochromic layer 3 was oxidized from green to dark blue, and the second electrochromic layer 5 was reduced from gray-black to yellow. By cycling a forward voltage (1.2V) and a reverse voltage (-1.0V) to the device, the color of the device can achieve color transformation.

[0203] The electrochromic device according to this embodiment may be used in end products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices.

[0204] Example 11

[0205] This example provides an electrochromic device, which is different from Example 7 in the following points: the amount of poly-2-[(2-ethylhexyloxy)methyl]3,4-thieno-1,4-dioxane weighed in the preparation of the first electrochromic layer 3 is 20 mg, the spin-coated thickness is 6 nm, and the maximum charge transfer rate per unit area is 0.1 C / cm 2 the thickness of the second electrochromic layer 5 is 25 nm, and the maximum charge transfer rate per unit area is 5 C / cm 2 The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer 3 and the second electrochromic layer 5 is 0.02:1.

[0206] The electrochromic device of this example was pretreated by applying a forward voltage (1.8 V) and then cycled through reverse voltage (-1.0 V) and forward voltage (1 V) to convert the color of the device between colorless and superimposed colors (off black and blue-purple).

[0207] The electrochromic device according to this embodiment may be used in end products such as consumer electronic products, electronic labels, doors and windows, cabinets, wearable devices, intelligent glasses, and phototherapy devices.

[0208] Comparative Example 1

[0209] Color conversion was performed using the electrochromic device of Example 1. The method differed from Example 1 in the following respects: Color conversion was performed by directly applying a forward voltage (1.2 V) and a reverse voltage (−1.2 V) to the device in a cycle.

[0210] (1) When a forward voltage (1.2 V) was applied to the device, the first electrochromic layer 3 was unable to lose electrons to cause an oxidation reaction, and the second electrochromic layer 5 was unable to gain electrons to cause a reduction reaction, so that neither the first electrochromic layer 3 nor the second electrochromic layer 5 changed color.

[0211] (2) When a reverse voltage (−1.2 V) was applied to the device, the first electrochromic layer 3 was unable to gain electrons to cause a reduction reaction, and the second electrochromic layer 5 was unable to lose electrons to cause an oxidation reaction, so that neither the first electrochromic layer 3 nor the second electrochromic layer 5 changed color.

[0212] (3) When forward voltage (1.2V) and reverse voltage (-1.2V) are cycled, the color of the device cannot be changed.

[0213] Both the first electrochromic layer 3 and the second electrochromic layer 5 are anodic electrochromic reduced state coloring materials, and because they are initially in a reduced state, the applied potential is too low to provide sufficient charge to oxidize and bleach the materials, and therefore the device is unable to perform color conversion.

[0214] The above is merely a specific embodiment of the present application, and the applicant declares that the scope of protection of the present application is not limited thereto. It should be understood that any modifications or replacements that can be easily conceived within the technical scope disclosed in the present application by those skilled in the art are all included in the scope of protection and disclosure of the present application. [Explanation of symbols]

[0215] 1 first base; 2 first transparent conductive layer; 3 first electrochromic layer; 4 electrolyte layer; 5 second electrochromic layer; 6 second transparent conductive layer; 7 second base.

Claims

1. 1. An electrochromic device comprising, stacked in sequence, a first base, a first transparent conductive layer, a first electrochromic layer, an electrolyte layer, a second electrochromic layer, a second transparent conductive layer, and a second base, the materials of the first electrochromic layer and the second electrochromic layer are both cathodic electrochromic materials, or the materials of the first electrochromic layer and the second electrochromic layer are both anodic electrochromic materials; the electrochromic device is pretreated by applying a first voltage in a first direction to the electrochromic device, causing the first electrochromic layer to change from a first color to a third color and maintaining the second electrochromic layer at a second color; the first color, the second color, and the third color are different from each other; Electrochromic device.

2. the first transparent conductive layer and the second transparent conductive layer each independently comprise at least one of indium tin oxide, zinc aluminum oxide, fluorine doped tin oxide, silver nanowires, graphene, carbon nanotubes, metal grids, and silver nanoparticles; The electrochromic device of claim 1 .

3. The first transparent conductive layer and the second transparent conductive layer each have a thickness of 1 to 1000 nm.

3. The electrochromic device according to claim 1 or 2.

4. the materials of the first electrochromic layer and the second electrochromic layer are not simultaneously cathodic electrochromic polychromic materials and not simultaneously anodic electrochromic polychromic materials; The electrochromic device according to any one of claims 1 to 3.

5. the materials of the first electrochromic layer and the second electrochromic layer are neither cathodic electrochromic polychromic materials, and neither anodic electrochromic polychromic materials; 5. The electrochromic device according to claim 1.

6. the materials of the first electrochromic layer and the second electrochromic layer are simultaneously cathodic electrochromic reduced state coloring materials, simultaneously cathodic electrochromic oxidized state coloring materials, simultaneously anodic electrochromic reduced state coloring materials, or simultaneously anodic electrochromic oxidized state coloring materials; 6. The electrochromic device according to claim 1 .

7. The maximum charge transfer rate per unit area of ​​the first electrochromic layer is 0 to 35 C / cm ２ and does not include 0, The maximum charge transfer rate per unit area of ​​the second electrochromic layer is 0 to 35 C / cm ２ and does not include 0; 7. The electrochromic device according to claim 1.

8. The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer and the second electrochromic layer is 1:50 to 50:

1.

8. An electrochromic device according to any one of claims 1 to 7.

9. The ratio of the maximum charge transfer numbers per unit area between the first electrochromic layer and the second electrochromic layer is 1:10 to 10:

1.

9. The electrochromic device according to claim 1 .

10. The electrolyte layer is a gel electrolyte layer, a liquid electrolyte layer, or a solid electrolyte layer.

10. The electrochromic device according to any one of claims 1 to 9.

11. The thickness of the electrolyte layer is 0.1 to 200 μm.

11. An electrochromic device according to any one of claims 1 to 10.

12. the material of the first base and the material of the second base are each independently glass or a flexible material; 12. An electrochromic device according to any one of claims 1 to 11.

13. A method for changing the color of the electrochromic device according to any one of claims 1 to 12, comprising the steps of: (1) applying a second voltage in a second direction opposite to the first direction to a pre-treated electrochromic device, causing the first electrochromic layer to change from a third color to the first color and the second electrochromic layer to change from a second color to a fourth color, the pre-treatment comprising applying a first voltage in a first direction to the electrochromic device, causing the first electrochromic layer to change from the first color to a third color and maintaining the second electrochromic layer at the second color; (2) applying a third voltage in a first direction to the pre-treated electrochromic device, thereby causing the first electrochromic layer to change from the first color to a third color and the second electrochromic layer to change from a fourth color to a second color. Discoloration method.

14. The absolute value of the first voltage is a critical voltage V that causes an irreversible electrochemical reaction in the second electrochromic layer. １ The color changing method according to claim 13.

15. the absolute value of the third voltage is less than the absolute value of the first voltage; The method for changing color according to claim 14.

16. Comprising an electrochromic device according to any one of claims 1 to 12. Electronic device.

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