Copper-silver-zinc ternary synergistic electrochromic material, device and preparation method of copper-silver-zinc ternary synergistic electrochromic material

Abstract

The invention discloses a copper-silver-zinc ternary synergistic electrochromic material, a device and a preparation method thereof, and relates to the technical field of electrochemical devices. The material comprises a metal salt, an electrolyte component and a solvent system, wherein the metal salt comprises a copper salt, a silver salt and a zinc salt; the material is prepared by the following method: stirring a solvent system and an electrolyte component, then adding a copper salt, a silver salt and a zinc salt, and continuously stirring to obtain the material, the device comprises a first transparent conductive substrate, an electrochromic material layer and a second transparent conductive substrate, the electrochromic device is prepared by the following method: coating the surface of a first transparent conductive substrate with the material to form an electrochromic material layer, then attaching a second transparent conductive substrate to the first transparent conductive substrate, sealing the edges of the first transparent conductive substrate and the second transparent conductive substrate, and finally arranging a conductive adhesive tape or a wire to obtain the electrochromic device. According to the invention, obvious transmittance change can be generated under low voltage, and the color change process is quicker.

Description

Technical Field

[0001] This invention relates to the field of electrochemical device technology, specifically to a copper-silver-zinc ternary synergistic electrochromic material, device, and preparation method thereof. Background Technology

[0002] Electrochromic technology refers to the technology that allows materials to undergo stable and reversible changes in optical performance parameters such as transmittance, reflectance, and absorptivity under the excitation of an applied electric field. This typically manifests as changes in color, transparency, or reflective appearance, and it has been widely applied in fields such as smart windows in buildings, automotive sunroofs, and anti-glare rearview mirrors. Among these, electrochromic systems based on the principle of metal electrodeposition achieve switching between a transparent state and a high-reflectance state through the reversible deposition and dissolution of metal ions on the electrode surface. Due to its advantages such as high optical contrast, fast response speed, and relatively simple device structure, it represents an important development direction for current electrochromic technology. Its core principle is that metal ions in solution undergo electrochemical reduction on the electrode surface under the drive of an applied electric field, forming a metal atomic layer that is deposited on a transparent electrode. When a reverse voltage is applied, the deposited metal layer can be oxidized and redissolved back into metal ions, restoring the device to a transparent state, thus achieving a reversible transition between the transparent and metallic states. This mechanism does not require complex multilayer inorganic thin film structures; it relies on the deposition and dissolution of metals to achieve the control of color and reflectance.

[0003] However, existing metal electrodeposition electrochromic systems mainly rely on single or binary metal systems such as silver or silver-copper. Although these systems can achieve certain optical modulation, they generally suffer from problems such as low nucleation density, coarse deposited layers, the need for higher driving voltages, limited cycle life, slow deposition rates under low voltage conditions, discontinuous film formation, and insufficient cycle stability. Especially in large-area devices, the ohmic voltage drop and interface polarization effect of the electrolyte layer are more pronounced, often requiring higher applied voltages to achieve ideal light-shielding and reflection effects. This leads to increased energy consumption, deterioration of deposition morphology, and reduced device lifespan, severely restricting the promotion of metal electrodeposition electrochromic technology in low-power and large-scale applications. In particular, phenomena such as island growth and dendrite formation can lead to inhomogeneous reflective layers and poor optical consistency, severely limiting the quality and reliability of electrochromic mirror devices.

[0004] Based on the above problems, there is an urgent need in the field for an electrochromic material system that can achieve rapid and uniform metal deposition under low driving voltage conditions, so as to balance low energy consumption, high optical modulation capability and good stability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a ternary synergistic electrochromic material, device, and its preparation method.

[0006] The technical solution adopted in this invention is: In a first aspect, the present invention provides a copper-silver-zinc ternary synergistic electrochromic material, comprising the following components: a metal salt, an electrolyte component, and a solvent system; wherein the molar ratio of the metal salt and the electrolyte component is 9:20 to 4:5, and the solvent system is used to fully dissolve the metal salt and the electrolyte component; Further, the metal salt includes copper salt, silver salt, and zinc salt, wherein the copper salt is CuCl2, the silver salt is AgNO3, and the zinc salt is ZnBr2 or ZnCl2; wherein the molar ratio of copper salt, silver salt, and zinc salt is 3:1:0 to 20:1:7.

[0007] Furthermore, the electrolyte component is selected from tetrabutylammonium bromide, butylammonium bromide, lithium salt, and sodium salt; wherein the lithium salt is LiCl, LiBr, or LiTFSI; and the sodium salt is NaCl or NaBr.

[0008] Furthermore, the solvent system is a polar organic solvent or a gel monomer; the polar organic solvent is composed of one or more of N-methylpyrrolidone, dimethyl sulfoxide, propylene carbonate, ethylene carbonate, and N,N-dimethylformamide mixed in any proportion; the gel monomer is polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, or methacrylic anhydride gelatin.

[0009] Furthermore, when the solvent system is a polar organic solvent, the material is in a liquid state.

[0010] Furthermore, when the solvent system is a gel monomer, a photoinitiator also needs to be added; wherein, the molar ratio of the photoinitiator to the total molar amount of the metal ions is in the range of 1:200 to 1:2, and the material is in a gel state.

[0011] Secondly, the present invention provides a method for preparing the above-mentioned electrochromic material, the method being: adding the electrolyte component to a solvent system, stirring and dissolving until clear, then adding a metal salt, and continuing to stir until fully dissolved, thereby obtaining a ternary synergistic electrochromic material.

[0012] Thirdly, the present invention provides an electrochromic device prepared from the above-mentioned electrochromic material, comprising a first transparent conductive substrate (1), an electrochromic material layer (2), and a second transparent conductive substrate (3), wherein the electrochromic material layer (2) is disposed between the two transparent conductive substrates.

[0013] Furthermore, the first transparent conductive substrate and the second transparent conductive substrate (3) include a transparent substrate layer and a transparent conductive layer, wherein the transparent substrate layer is glass and the transparent conductive layer is selected from ITO material, FTO material and AZO material.

[0014] Furthermore, the electrochromic material layer (2) has a thickness of 10~500μm.

[0015] Fourthly, the present invention provides a method for preparing the above-mentioned electrochromic device, comprising the following steps: S1: The first transparent conductive substrate (1) and the second transparent conductive substrate (3) are cleaned with organic solvent, ultrasonically treated and dried. S2: Subsequently, the prepared electrochromic material is coated or injected onto the surface of the transparent conductive layer of the first transparent conductive substrate to form an electrochromic material layer (2), and the thickness of the electrochromic material layer (2) is controlled. S3: Then, the side of the second transparent conductive substrate (3) containing the transparent conductive layer is aligned and bonded with the side of the first transparent conductive substrate (1) containing the transparent conductive layer, so that the electrochromic material layer (2) is sandwiched between the two transparent conductive layers to form a sandwich structure, and the edge of the device is sealed. S4: Finally, conductive tape or wires are placed at the edges of the transparent conductive layers on both sides of the device to lead out the external electrodes, thus obtaining the electrochromic device.

[0016] Furthermore, when the electrochromic material is in a gel state, it needs to be photocured under a 365nm UV lamp after the sealing treatment in step S3.

[0017] Furthermore, the sealing material is selected from epoxy resin and UV-curable adhesive.

[0018] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in the following aspects: (1) Achieving effective electrochromism at a lower driving voltage and reducing the device operating voltage. In the specific embodiment, under the condition of keeping the concentrations of silver ions and copper ions constant, after introducing zinc ions, the device can produce a significant change in transmittance at a lower driving voltage, while the control system without the introduction of zinc ions usually requires a larger voltage to achieve a considerable degree of color change effect.

[0019] (2) Improve the deposition kinetics under low voltage conditions and accelerate the color change response speed. Under the same driving voltage conditions, the example with zinc ions introduced showed earlier metal deposition, more obvious current response, and faster color change process compared with the control example without zinc.

[0020] (3) Achieving a controllable deposition process of “nucleation-growth-film formation” and improving deposition uniformity. In the ternary metal system of the present invention, copper ions preferentially undergo reduction and form initial nucleation sites, zinc ions regulate the nucleation behavior at the interface, and silver ions grow rapidly at the nucleation sites and gradually form a continuous metal film. Attached Figure Description

[0021] Figure 1 A schematic diagram of the electrochromic device structure; Figure 2 This is a schematic diagram of the ternary electrodeposition mechanism; Figure 3 The images show the effect of the device before and after color change, where a is the effect before color change and b is the effect after color change. Reference numerals: First transparent conductive substrate-1, electrochromic material layer-2, second transparent conductive substrate-3. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0024] This invention proposes a copper-silver-zinc ternary synergistic electrochromic material, device, and its preparation method. By introducing zinc ions into the electrodeposition process, the nucleation and growth behavior of silver and copper are synergistically regulated, thereby effectively reducing the electrochemical driving force requirement for metal deposition and achieving a dense and continuous metal deposition layer under lower voltage conditions. This invention has certain advantages in reducing device operating voltage, increasing color-changing speed, and improving optical control performance.

[0025] In a first aspect, the present invention provides a copper-silver-zinc ternary synergistic electrochromic material, comprising a metal salt, an electrolyte component, and a solvent system, wherein: Metal salts: including copper salts, silver salts, and zinc salts, specifically AgNO3, CuCl2, ZnBr2, ZnCl2, and other related metal salts.

[0026] The copper, silver, and zinc salts are used to ionize Cu. 2+ Ag + Zn 2+ Among them, Ag + Used to form highly reflective metallic layers, Cu is a major electrochromic metal. 2+ Used to regulate color and nucleation behavior in the early stages of deposition; Zn 2+ It is used to synergistically regulate the metal deposition process and improve nucleation density and deposition uniformity.

[0027] The concentration ranges of each metal ion are as follows: Ag +: 0.01–0.50 mol / L; Cu 2+ : 0.001–0.10 mol / L; Zn 2+ : 0.001–0.10 mol / L.

[0028] Electrolyte components: Electrolytes are used to improve the ionic conductivity of the system. The preferred electrolytes are quaternary ammonium salts and alkali metal salts, including tetrabutylammonium bromide, butylammonium bromide, lithium salts (LiCl, LiBr, LiTFSI), and sodium salts (NaCl, NaBr), with a concentration range of 0.05–1.0 mol / L.

[0029] Solvent system: The solvent is used to dissolve the metal salt and electrolyte to form a uniform electrochromic material system. It is preferably a polar organic solvent, including one or more of N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), propylene carbonate (PC), ethylene carbonate (EC), and N,N-dimethylformamide (DMF).

[0030] Gel monomers: Gel monomers are used to dissolve metal salts and electrolytes to form a uniform electrochromic material system. After adding a photoinitiator, they can be cured to obtain gel polymers, including polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), and methacrylic anhydride gelatin (GelMA). Compared with pure liquid, the stability and safety of gel state are further improved.

[0031] The above components, when mixed, form a reversible metal electrodeposition electrochromic material. Only one of the solvent or gel monomer is selected. Under an applied electric field, metal ions undergo directional migration and deposit on the electrode surface to form a metal layer. Macroscopically, this manifests as reversible changes in the device's transmittance, reflectance, and color. The specific reaction mechanism is as follows: Figure 2 As shown in the schematic diagram, the electrochromic device of this invention exhibits typical ternary metal synergistic electrodeposition behavior under an applied electric field: In the initial transparent state, silver, copper, and zinc ions are uniformly distributed in the electrochromic functional layer; when a voltage is applied, the metal ions migrate directionally under the drive of the electric field. Copper ions, due to their low nucleation overpotential, preferentially undergo reduction on the surface of the transparent conductive cathode electrode and form dispersed nucleation sites. Zinc ions are enriched at the electrode / electrolyte interface and regulate the electric bilayer structure, thereby reducing the energy barrier for subsequent metal deposition. Based on this, silver ions rapidly reduce and grow along the existing copper nucleation sites, and the deposition layer gradually develops from discrete nucleation into a continuous metal film, significantly reducing the visible light transmittance of the device and exhibiting enhanced reflectivity. On the anode side, only interface polarization and charge compensation occur, without metal deposition. Under the action of a reverse voltage, the above metal deposition process is reversible, realizing stable and reversible electrochromic control from a dark state to a transparent state.

[0032] The copper-silver-zinc ternary synergistic electrochromic material is a homogeneous liquid or gel electrolyte system.

[0033] Secondly, the present invention provides a method for preparing a copper-silver-zinc ternary synergistic electrochromic material.

[0034] The preparation method is specifically as follows: The solvent system and electrolyte components are dissolved until clear under magnetic stirring. Then, silver salt, copper salt and zinc salt are added and stirred until fully dissolved to obtain the ternary electrochromic material.

[0035] Thirdly, the present invention also provides an electrochromic device.

[0036] like Figure 1 As shown, its structure is a sandwich structure, including: a first transparent conductive substrate 1, an electrochromic material layer 2, and a second transparent conductive substrate 3; wherein, the electrochromic material layer 2 is disposed between the two transparent conductive substrates.

[0037] The transparent conductive substrate includes a transparent substrate layer and a transparent conductive layer. The transparent substrate layer is glass, and the transparent conductive layer is selected from transparent conductive materials such as ITO, FTO, and AZO.

[0038] The electrochromic material layer (2) has a thickness of 10~500μm; its morphology includes liquid and gel states.

[0039] Its structural features are as follows: Metal ions are uniformly distributed in a solvent system in a dissolved state; under the action of an applied electric field, the metal ions undergo directional migration; reversible electrodeposition occurs on the surface of a transparent conductive electrode, forming a continuous or semi-continuous metal layer; the deposited metal is dissolved by a reverse voltage.

[0040] Fourthly, the present invention also provides a method for preparing an electrochromic device using the above-mentioned copper-silver-zinc ternary synergistic electrochromic material, comprising the following steps: S1: The first transparent conductive substrate 1 and the second transparent conductive substrate 3 are sequentially cleaned with organic solvent, ultrasonically treated, and dried. S2: Subsequently, the copper-silver-zinc ternary synergistic electrochromic material prepared above is coated or injected onto the surface of the transparent conductive layer of the first transparent conductive substrate 1 to form an electrochromic material layer 2, and the thickness of the electrochromic material layer 2 is controlled by spacers, precision coating or liquid injection.

[0041] S3: Then, the side of the second transparent conductive substrate 3 containing the transparent conductive layer is aligned and bonded with the side of the first transparent conductive substrate 1 containing the transparent conductive layer, so that the electrochromic material layer 2 is sandwiched between the two transparent conductive layers to form a sandwich structure, and the edge of the device is sealed. The sealing material is selected from epoxy resin, UV curing adhesive or other sealing materials.

[0042] S4: Finally, conductive tape or wires are placed at the edges of the transparent conductive layers on both sides of the device to lead out the external electrodes, thus obtaining the electrochromic device.

[0043] This invention also provides a method for preparing a copper-silver-zinc ternary synergistic electrochromic gel device. The organic solvents mentioned above, such as NMP, are replaced with equal masses of monomers, such as polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and methacrylic anhydride gelatin. A photoinitiator is added, and after sealing, the device is photocured under a 365nm UV lamp to obtain the corresponding gel-state ternary synergistic electrochromic device.

[0044] Based on the above method, several embodiments were fabricated, and the device effects are as follows. Figure 3 As shown, it is transparent before the color change and becomes a specular reflection state after the color change.

[0045] Example 1: In Example 1, the molar ratio of silver salt, copper salt and zinc salt was 5:1:0 (i.e. no zinc ions were added to the system).

[0046] (1) Preparation of electrochromic material: Weigh 5.000 g of NMP and add it to a clean brown sample bottle. Add 0.7840 g of tetrabutylammonium bromide (TBAB) and dissolve it until clear under magnetic stirring. Then add 0.1032 g of AgNO3 and continue stirring until completely dissolved. Then add 0.0164 g of anhydrous CuCl2 and stir until the solution is clear and homogeneous to obtain an electrochromic material without zinc ions.

[0047] (2) Preparation of electrochromic device: ITO glass was used as the first transparent conductive substrate 1 and the second transparent conductive substrate 3, respectively. The substrates were sequentially cleaned with organic solvent, ultrasonically treated, and dried. Then, the prepared copper-silver-zinc ternary synergistic electrochromic material was injected into the surface of the transparent conductive layer of the first transparent conductive substrate. The thickness of the electrochromic material layer 2 was controlled by spacers, precision coating, or liquid injection. In this embodiment, the thickness was 10 μm. Next, the side of the second transparent conductive substrate 3 containing the transparent conductive layer was aligned and bonded to the side of the first transparent conductive substrate 1 containing the transparent conductive layer, so that the electrochromic material layer 2 was sandwiched between the two transparent conductive layers, forming a sandwich structure. The edges of the device were then sealed using UV-curable adhesive. Finally, conductive tape or wires were placed on the edges of the transparent conductive layers on both sides of the device to lead out external electrodes, thus obtaining the device of Example 1.

[0048] Example 2: In Example 2, the molar ratio of copper salt, silver salt and zinc salt is 25:5:1.

[0049] (1) Preparation of electrochromic material: Weigh 5.000 g of NMP and add it to a brown bottle. Add 0.7840 g of tetrabutylammonium bromide (TBAB) and stir until clear. Add 0.1032 g of AgNO3 and stir to dissolve. Add 0.0164 g of anhydrous CuCl2 and stir to dissolve. Finally, add 0.0033 g of ZnCl2 (corresponding to Zn 2+ =0.005 M) Continue stirring until the solution is homogeneous and clear to obtain a ternary metal electrochromic material containing zinc ions.

[0050] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0051] Example 3: In Example 3, the molar ratio of copper salt, silver salt, and zinc salt is 10:2:1. (1) Preparation of electrochromic material: Weigh 5.000 g of NMP, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and stir to dissolve; add 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0079 g (7.9 mg) of ZnCl2 and continue stirring until homogeneous and clear.

[0052] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0053] Example 4: In Example 4, the molar ratio of copper salt, silver salt, and zinc salt is 25:5:4. (1) Preparation of electrochromic material: Weigh 5.000 g of NMP, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 in sequence and stir until clear; add 0.0132 g (13.2 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous.

[0054] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0055] Example 5: In Example 5, the molar ratio of copper salt, silver salt, and zinc salt is 5:1:1. (1) Preparation of electrochromic material: Weigh 5.000 g of NMP, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous.

[0056] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0057] Example 6: In Example 6, the molar ratio of copper salt, silver salt and zinc salt is 5:1:1, the same as in Example 5. The only difference is that the solvent is replaced with propylene carbonate. The steps for preparing electrochromic materials and electrochromic devices are the same as in Example 5, and will not be repeated here.

[0058] Example 7: In Example 7, the molar ratio of copper salt, silver salt and zinc salt is 5:1:1, the same as in Example 5, except that the solvent is replaced with polyethylene glycol diacrylate.

[0059] (1) Preparation of electrochromic material: Weigh 5.000 g of polyethylene glycol diacrylate, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous; add 0.01 g of photoinitiator and continue stirring until the solution is clear and homogeneous.

[0060] Fabrication of the electrochromic device: ITO glass was used as the first transparent conductive substrate 1 and the second transparent conductive substrate 3, respectively. These substrates were sequentially cleaned with organic solvents, ultrasonically treated, and dried. Then, the copper-silver-zinc ternary synergistic electrochromic material prepared above was injected into the surface of the transparent conductive layer of the first transparent conductive substrate 1. The thickness of the electrochromic material layer was controlled to be 200 μm using spacers, precision coating, or liquid injection methods. Next, the side of the second transparent conductive substrate 3 containing the transparent conductive layer was aligned and bonded to the side of the first transparent conductive substrate 1 containing the transparent conductive layer, sandwiching the electrochromic material layer between the two transparent conductive layers to form a sandwich structure. The edges of the device were then sealed using a UV-curable adhesive. After sealing, the liquid was cured into a gel by irradiation with a 365 nm UV lamp for three minutes, yielding a gel-state electrochromic electrolyte. Conductive tapes or wires were placed at the edges of the transparent conductive layers on both sides of the device to lead out external electrodes, thus fabricating the device of Example 7.

[0061] Example 8: In Example 8, the solvent was changed from polyethylene glycol diacrylate in Example 7 to polyethylene glycol dimethacrylate. The steps for preparing the electrochromic material and the electrochromic device were the same as in Example 7, and will not be repeated here.

[0062] Example 9: In Example 9, the solvent was changed from polyethylene glycol diacrylate in Example 7 to methacrylic anhydride gelatin. The steps for preparing the electrochromic material and the electrochromic device were the same as in Example 7, and will not be repeated here.

[0063] Example 10: In Example 10, the molar ratio of copper salt, silver salt, and zinc salt is 5:1:1, the same as in Example 5. The only difference is that the solvent is replaced with dimethyl sulfoxide. The steps for preparing the electrochromic material and the electrochromic device are the same as in Example 5, and will not be repeated here.

[0064] Example 11: In Example 11, the molar ratio of copper salt, silver salt, and zinc salt is 5:1:1, the same as in Example 5. The only difference is that the solvent is replaced with ethylene carbonate. The steps for preparing the electrochromic material and the electrochromic device are the same as in Example 5, and will not be repeated here.

[0065] Example 12: In Example 12, the molar ratio of copper salt, silver salt, and zinc salt is 5:1:1, the same as in Example 5. The only difference is that the solvent is replaced with N,N-dimethylformamide. The steps for preparing the electrochromic material and the electrochromic device are the same as in Example 5, and will not be repeated here.

[0066] Example 13: Butylammonium bromide was used instead of tetrabutylammonium bromide. 5.000 g of NMP was weighed and added to a clean brown sample bottle, followed by 0.3356 g of butylammonium bromide (BABr). The solution was dissolved until clear under magnetic stirring. Then, 0.1032 g of AgNO3 was added and stirring continued until completely dissolved. Finally, 0.0164 g of anhydrous CuCl2 was added and stirring continued until the solution was clear and homogeneous, yielding an electrochromic material free of zinc ions.

[0067] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0068] Example 14: LiTFSI was used instead of tetrabutylammonium bromide. 5.000 g of NMP was weighed and added to a clean brown sample vial. 0.6976 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was added and dissolved until clear under magnetic stirring. Then, 0.1032 g of AgNO3 was added and stirring continued until completely dissolved. Finally, 0.0164 g of anhydrous CuCl2 was added and stirring continued until the solution was clear and homogeneous, yielding an electrochromic material free of zinc ions.

[0069] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0070] Example 15: Replace tetrabutylammonium bromide with NaCl. Weigh 5.000 g of NMP and add it to a clean brown sample bottle. Add 0.1421 g of sodium chloride (NaCl) and dissolve it until clear under magnetic stirring. Then add 0.1032 g of AgNO3 and continue stirring until completely dissolved. Finally, add 0.0164 g of anhydrous CuCl2 and stir until the solution is clear and homogeneous to obtain an electrochromic material that does not contain zinc ions.

[0071] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0072] Example 16: Replace tetrabutylammonium bromide with NaBr. Weigh 5.000 g of NMP and add it to a clean brown sample bottle. Add 0.2500 g of sodium bromide (NaBr) and dissolve it until clear under magnetic stirring. Then add 0.1032 g of AgNO3 and continue stirring until completely dissolved. Finally, add 0.0164 g of anhydrous CuCl2 and stir until the solution is clear and homogeneous to obtain an electrochromic material that does not contain zinc ions.

[0073] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0074] Example 17: (1) Preparation of electrolyte solution: Weigh 5.000 g of NMP, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous.

[0075] (2) Preparation of the electrochromic device: FTO glass and AZO glass were used as the first and second transparent conductive substrates, respectively. They were sequentially cleaned with organic solvents, ultrasonically treated, and dried. Then, the side of the second transparent conductive substrate 3 containing the transparent conductive layer was aligned and bonded to the side of the first transparent conductive substrate 1 containing the transparent conductive layer. The thickness of the electrochromic material layer was controlled to be 480 μm using spacers, precision coating, or liquid injection. The second transparent conductive substrate was then aligned and bonded to the first transparent conductive substrate, sandwiching the electrochromic material layer between the two transparent conductive layers to form a sandwich structure. The edges of the device were sealed with epoxy resin. Finally, conductive tape or wires were placed at the edges of the transparent conductive layers on both sides of the device to lead out external electrodes, thus obtaining the device of Example 1.

[0076] Example 18: (1) Preparation of electrochromic material: Weigh 3.000 g of NMP, 1.000 g of dimethyl sulfoxide, and 1.000 g of ethylene carbonate, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous.

[0077] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0078] Example 19: (1) Preparation of electrochromic material: Weigh 3.000 g of propylene carbonate, 2.000 g of N,N-dimethylformamide, and 0.7840 g of carbon into TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous.

[0079] The steps for preparing the electrochromic device are the same as in Example 1, and will not be repeated here.

[0080] Example 20: The only difference from Example 7 is that the amount of photoinitiator used in Example 7 is changed to 0.001g.

[0081] (1) Preparation of electrochromic material: Weigh 5.000 g of polyethylene glycol diacrylate, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous; add 0.001 g of photoinitiator and continue stirring until the solution is clear and homogeneous.

[0082] The steps for preparing the electrochromic device are the same as in Example 7, and will not be repeated here.

[0083] Example 21: The only difference from Example 7 is that the amount of photoinitiator used in Example 7 is changed to 0.015g. (1) Preparation of electrochromic material: Weigh 5.000 g of polyethylene glycol diacrylate, add 0.7840 g of TBAB and stir to dissolve; add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until clear; add 0.0198 g (19.8 mg) of ZnCl2 and continue stirring until the solution is clear and homogeneous; add 0.015 g of photoinitiator and continue stirring until the solution is clear and homogeneous.

[0084] The steps for preparing the electrochromic device are the same as in Example 7, and will not be repeated here.

[0085] Comparative Example 1: Ternary systems in which zinc ions are replaced by magnesium ions: Weigh 5.000 g of NMP into a brown sample vial, add 0.7840 g of TBAB and stir until dissolved and clear; then add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until completely dissolved; finally add 0.00926 g of anhydrous MgCl2 (to make Mg... 2+ The concentration is 0.020 M, which is similar to the optimal Zn. 2+ (Keep the concentration consistent) Continue stirring until the solution is homogeneous and clear. If necessary, filter and degas to obtain the electrolyte solution of Comparative Example 1.

[0086] The remaining process is the same as in Example 1 above, and will not be repeated here.

[0087] Comparative Example 2: Ternary systems where zinc ions are replaced by potassium ions: Weigh 5.000 g of NMP into a brown sample vial, add 0.7840 g of TBAB and stir until clear; then add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 and stir until completely dissolved; finally add 0.00725 g of KCl (corresponding to K + =0.020 M, and the optimal Zn 2+ Continue stirring at a concentration of 1:1 until the solution is homogeneous and clear to obtain the electrolyte solution of Comparative Example 2.

[0088] The remaining process is the same as in Example 1 above, and will not be repeated here.

[0089] Comparative Example 3: Ternary system with ZnCl2 replaced by ZnBr2: Weigh 5.000 g of NMP into a brown sample vial, add 0.7840 g of TBAB, and stir magnetically until completely dissolved to form a clear solution; then add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 sequentially, stirring continuously until completely dissolved; finally add 0.0219 g of ZnBr2 (corresponding to Zn 2+ =0.020 M) Continue stirring until the solution is clear and homogeneous to obtain the electrolyte solution of Comparative Example 1.

[0090] The remaining process is the same as in Example 1 above, and will not be repeated here.

[0091] Comparative Example 4: Ternary system with ZnCl2 replaced by BiCl3: Weigh 5.000 g of NMP into a brown sample vial, add 0.7840 g of TBAB, and dissolve under magnetic stirring until the solution is clear; then add 0.1032 g of AgNO3 and 0.0164 g of anhydrous CuCl2 sequentially, and continue stirring until completely dissolved; add 0.0154 g of BiCl3 to the above solution, so that Bi... 3+ (Concentration 0.020 M), continue stirring until the solution is clear and homogeneous, to obtain Bi-containing solution. 3+ Electrolyte solution.

[0092] The remaining process is the same as in Example 1, and will not be repeated here.

[0093] Based on the above method, several experimental examples and comparative examples were prepared. In the examples, the experimental analysis was mainly conducted by fixing the silver-copper ratio (5:1) and changing the zinc content, as well as by changing the electrolyte and solvent at the optimal zinc content. The comparative examples mainly involved replacing zinc chloride with other equimolar amounts of substances. The specific data of the device performance parameters obtained from the examples and comparative examples are shown in Tables 1 and 2, respectively. Table 1. Performance parameters of devices prepared in the examples

[0094] Table 2 Performance parameters of devices prepared in the comparative example

[0095] The experimental results from the above embodiments and comparative examples show that the electrochromic system based on the synergistic electrodeposition of silver-copper-zinc ternary metals described in this invention exhibits significantly better overall performance than the comparative system under low-voltage driving conditions. In the embodiments, by introducing an appropriate amount of zinc chloride while keeping the concentrations of silver and copper ions constant, the device can achieve significant current response and optical transmittance modulation at a lower driving voltage. Furthermore, with increasing zinc ion concentration, the optical control capability and color-changing speed of the device in the ultraviolet, visible, and infrared bands are effectively improved, indicating that the introduction of zinc ions can significantly improve the kinetics of metal deposition and reduce the apparent deposition overpotential.

[0096] In the comparative examples, after replacing zinc chloride with zinc bromide, although the type of anion changed, the color-changing behavior and kinetic characteristics of the device at low voltage were similar to those in the examples, indicating that zinc ions play a key synergistic role in the device, rather than anions. When potassium chloride was used to replace zinc chloride, although equimolar concentrations of potassium and chloride ions were introduced, the color-changing ability of the device at low voltage was significantly insufficient, indicating that the improvement of monovalent alkali metal ions and ionic strength cannot replace the synergistic effect of zinc ions in this system. Further comparison results using magnesium chloride to replace zinc chloride showed that even with the introduction of divalent metal ions, the device performance still could not reach the level of the zinc system in the examples, proving that the technical effect described in this invention is not universally achieved by "any divalent metal ions", but rather stems from the unique role of zinc ions in the electrode / electrolyte interface regulation and nucleation process.

[0097] Furthermore, in a further comparative example, after replacing zinc ions with bismuth ions, the device still exhibited a certain degree of color-changing response and improved kinetics under low voltage conditions, indicating that bismuth ions can also participate in interface modulation and influence metal deposition behavior to some extent. However, compared with the zinc-containing example, the bismuth-containing system still differs in color-changing speed, stability, and overall optical control capability, suggesting that although bismuth ions can play a certain auxiliary role, zinc ions still exhibit a more preferred synergistic effect in the system of this invention.

[0098] Further analysis of the results from implementations with different zinc salt types and concentration gradients reveals that zinc ions do not participate as the primary deposited metal in the system of this invention to form a thick metal layer. Instead, they significantly influence the nucleation and growth behavior of silver and copper by regulating the electrochemical environment at the electrode / electrolyte interface. Within a suitable concentration range, the introduction of zinc ions can increase the metal nucleation density, inhibit localized overgrowth, and improve deposition uniformity, thereby promoting the formation of a continuous metal deposition layer under lower voltage conditions. This allows the device to achieve better optical control while maintaining rapid color change. Conversely, when the zinc ion content is too low or too high, the device performance decreases to varying degrees, indicating that zinc ions have a reasonable effective operating range in the system of this invention. This has also been verified through multiple concentration gradient examples.

[0099] The comparative experiments conducted in the examples, which involved changing the type of zinc salt anion (such as zinc chloride and zinc bromide) and the type of supporting electrolyte, demonstrate that, while maintaining the presence of zinc ions, the device can still achieve a stable electrochromic response at low voltage. This further illustrates that the core technical effect of the present invention stems from the synergistic effect of zinc ions in interface regulation and deposition kinetics, rather than simply relying on a specific anion or electrolyte system. This compatibility with electrolyte components and metal salt types gives the system of the present invention a degree of flexibility and scalability in material selection and formulation design.

[0100] The results from the various embodiments and comparative examples further confirm that the copper-silver-zinc ternary synergistic electrodeposition system proposed in this invention achieves synergistic optimization of the metal nucleation, growth, and dissolution processes by rationally controlling the molar ratio of the three metal ions and electrolyte conditions. This results in significant advantages in reducing driving voltage, increasing color change speed, improving optical control capabilities, and enhancing cycle stability. This synergistic mechanism avoids the problems of uneven deposition, slow response, or high energy consumption that are common in single-metal deposition systems, while overcoming the difficulty in stably controlling deposition behavior in simple multi-metal mixture systems.

[0101] Therefore, this invention not only achieves electrochromic effects with low voltage, high response speed and good reversibility at the performance level, but also provides a meaningful multi-metal synergistic electrodeposition approach at the material system and process design level, providing a new solution for the application of electrochromic devices in smart windows, automotive sunroofs, anti-glare displays and other optical control fields.

[0102] Without departing from the overall technical concept of the present invention, the copper-silver-zinc ternary synergistic electrochromic material and device of the present invention can also be implemented by the following alternative solutions or equivalent solutions.

[0103] Regarding the metal ion system, in addition to silver ions, copper ions, and zinc ions, the zinc ions in this invention can be partially or completely replaced by other metal ions with interface regulation or synergistic deposition effects, such as the bismuth ions mentioned in the comparative example. The aforementioned alternative metal ions can participate in the electrodeposition process together with silver ions and copper ions to regulate metal nucleation behavior, deposition morphology, or deposition rate. Their mechanism of action is the same as or similar to the synergistic regulation effect of zinc ions in this invention, and both belong to the equivalent alternatives of this invention.

[0104] Regarding the electrolyte system, the quaternary ammonium salt electrolyte used in this invention is not limited to tetrabutylammonium bromide, but can also be replaced by other quaternary ammonium salts, alkali metal salts or combinations thereof, such as butylammonium bromide, lithium salt (LiTFSI), sodium salt (sodium chloride, sodium bromide), potassium salt (potassium chloride), etc. As long as it can dissolve in the selected solvent system and provide an ionic conductive environment for the migration of metal ions and electrodeposition reaction, it can be used as an alternative electrolyte of this invention.

[0105] Regarding the solvent system, the polar organic solvent used in this invention is not limited to N-methylpyrrolidone, but can also be replaced by dimethyl sulfoxide, N,N-dimethylformamide, propylene carbonate, ethylene carbonate, ethylene glycol, or a mixture of the above solvents. As long as it can simultaneously dissolve the metal salt and electrolyte and meet the stability and electrochemical window requirements of the electrodeposition reaction, it can be used as an equivalent solvent scheme of this invention.

[0106] Regarding the gel used, in addition to polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and methacrylic anhydride gelatin mentioned in this invention, any material that can simultaneously dissolve metal salts and electrolytes, meet the stability and electrochemical window requirements for electrodeposition reactions, and can be cured can be used as an equivalent gel solution of this invention.

Claims

1. A copper-silver-zinc ternary synergistic electrochromic material, characterized in that, It includes the following components: metal salt, electrolyte component, and solvent system; wherein the molar ratio of metal salt to electrolyte component is 9:20 to 4:5, and the solvent system is used to fully dissolve the metal salt and electrolyte component; The metal salts include copper salts, silver salts, and zinc salts, wherein the copper salt is CuCl2, the silver salt is AgNO3, and the zinc salt is ZnBr2 or ZnCl2; wherein the molar ratio of copper salt, silver salt, and zinc salt is 3:1:0 to 20:1:

7. The electrolyte component is selected from tetrabutylammonium bromide, butylammonium bromide, lithium salt, and sodium salt; wherein the lithium salt is LiCl, LiBr, or LiTFSI; and the sodium salt is NaCl or NaBr. The solvent system is a polar organic solvent or a gel monomer; the polar organic solvent is composed of one or more of N-methylpyrrolidone, dimethyl sulfoxide, propylene carbonate, ethylene carbonate, and N,N-dimethylformamide mixed in any proportion; the gel monomer is polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, or methacrylic anhydride gelatin.

2. The electrochromic material according to claim 1, characterized in that, When the solvent system is a polar organic solvent, the material is in a liquid state.

3. The electrochromic material according to claim 1, characterized in that, When the solvent system is a gel monomer, a photoinitiator also needs to be added; wherein, the molar ratio of the photoinitiator to the total molar amount of the metal ions is in the range of 1:200 to 1:2, and the material is in a gel state.

4. A method for preparing the electrochromic material according to claim 1, characterized in that, The method is as follows: add the electrolyte component to the solvent system, stir to dissolve until clear, then add the metal salt, continue stirring to dissolve it completely, and the ternary synergistic electrochromic material can be obtained.

5. An electrochromic device prepared from the electrochromic material according to claim 1, characterized in that, It includes a first transparent conductive substrate (1), an electrochromic material layer (2), and a second transparent conductive substrate (3), wherein the electrochromic material layer (2) is disposed between the two transparent conductive substrates.

6. The device according to claim 5, characterized in that, The first transparent conductive substrate and the second transparent conductive substrate (3) include a transparent substrate layer and a transparent conductive layer. The transparent substrate layer is glass, and the transparent conductive layer is selected from ITO material, FTO material, and AZO material.

7. The device according to claim 5, characterized in that, The electrochromic material layer (2) has a thickness of 10~500μm.

8. A method for fabricating the device according to claim 5, characterized in that, Includes the following steps: S1: The first transparent conductive substrate (1) and the second transparent conductive substrate (3) are cleaned with organic solvent, ultrasonically treated and dried. S2: Subsequently, the prepared electrochromic material is coated or injected onto the surface of the transparent conductive layer of the first transparent conductive substrate to form an electrochromic material layer (2), and the thickness of the electrochromic material layer (2) is controlled. S3: Then, the side of the second transparent conductive substrate (3) containing the transparent conductive layer is aligned and bonded with the side of the first transparent conductive substrate (1) containing the transparent conductive layer, so that the electrochromic material layer (2) is sandwiched between the two transparent conductive layers to form a sandwich structure, and the edge of the device is sealed. S4: Finally, conductive tape or wires are placed at the edges of the transparent conductive layers on both sides of the device to lead out the external electrodes, thus obtaining the electrochromic device.

9. The method according to claim 8, characterized in that, When the electrochromic material is in a gel state, it needs to be photocured under a 365nm UV lamp after the sealing treatment in step S3.

10. The method according to claim 8 or 9, characterized in that, The sealing material is selected from epoxy resin and UV-curable adhesive.

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