High-performance electrochromic device and preparation method thereof

Abstract

The present application relates to a kind of high-performance electrochromic device and preparation method thereof.The high-performance electrochromic device includes: by sequentially layering by first transparent electrode layer, gradient crystallization electrochromic layer, gel electrolyte layer and second transparent electrode layer, and the multilayer layered structure unit is arranged in the packaging layer of the side of multilayer layered structure unit.

Description

Technical Field

[0001] This invention relates to a high-performance electrochromic device and its preparation method, belonging to the fields of chemical material synthesis and functional materials technology. Background Technology

[0002] Energy is a crucial foundation for maintaining a nation's sustained economic development and ensuring people's material well-being. Today, energy shortages and environmental pollution are increasingly severe, prompting scientists to develop new energy sources while simultaneously seeking methods to conserve energy and reduce consumption. Electrochromic devices and technologies are primarily applied in energy-efficient building glass, vehicle windows, anti-glare rearview mirrors, displays, electronic paper, and camouflage applications. Low-E glass is a type of low-emissivity glass that works by reflecting most infrared radiation, reducing heat entering the room. Insulating glass reduces heat exchange between the indoor and outdoor spaces. Both aim to reduce indoor cooling energy consumption. However, these two types of windows, and their combinations, only facilitate cooling, not temperature regulation. That is, in cold winters, heat still struggles to enter the room.

[0003] Traditional electrochromic devices mainly consist of five thin films: two transparent conductive layers, an ion storage layer, an electrochromic layer, and an ion conduction layer. The ion storage layer assists the electrochromic layer in achieving the electrochromic reaction by applying a low voltage to the first and second conductive layers. The ion conduction layer provides lithium ions and diffuses the thin film, ensuring ion conductivity under an electric field. Its structure and fabrication process are among the most important technologies for guaranteeing the electrochromic performance of the device.

[0004] All-solid-state electrochromic devices possess stable structures and excellent resistance to water, oxygen, and ultraviolet radiation, avoiding the drawbacks of liquid and quasi-solid-state devices. However, their slow response speed due to low ion migration rates limits their application areas. Furthermore, all-solid-state electrochromic devices are prone to uneven coloring after multiple cycles, making it difficult to design and fabricate large-size devices. Summary of the Invention

[0005] To address the poor cycle stability and environmental weather resistance of existing electrochromic devices, this invention provides a high-performance electrochromic device containing a gradient-crystallized electrochromic layer and an organic polymer encapsulation material, as well as its preparation method.

[0006] On one hand, the present invention provides a high-performance electrochromic device, comprising: a multilayered structure unit consisting of a first transparent electrode layer, a gradient-crystallized electrochromic layer, a gel electrolyte layer and a second transparent electrode layer stacked sequentially, and an encapsulation layer disposed on the side of the multilayered structure unit.

[0007] To address the common problems of defects and ion recombination in electrochromic materials, or ions recombinating at the electrode interface after passing through the electrochromic material, this invention creatively employs a gradient-crystallized electrochromic layer. This not only improves the diffusion kinetics of ions within the layer but also effectively prevents ions from migrating to the electrode surface under high voltage and recombinating with electrons to form irreversible defects.

[0008] Preferably, the gradient-crystallized electrochromic layer includes an inorganic crystalline layer and an inorganic amorphous layer distributed on the surface of the first transparent electrode layer, and the material of the gradient-crystallized electrochromic layer is at least one of WO3, MoO3 and TiO2; preferably, the surface roughness of the inorganic amorphous layer in the gradient-crystallized electrochromic layer is ≤0.5nm.

[0009] Furthermore, preferably, the thickness of the inorganic crystalline layer in the gradient-crystallized electrochromic layer is 200–600 nm, and the thickness of the inorganic amorphous layer is 50–300 nm; more preferably, the total thickness of the gradient-crystallized electrochromic layer is 500–800 nm.

[0010] Preferably, the gel electrolyte layer is obtained by photocuring a resin slurry of cationic salt;

[0011] The composition of the cationic resin slurry includes: photocurable resin, solvent, stabilizer, organic precursor and cationic salt; the mass ratio of the photocurable resin, solvent, stabilizer, organic precursor and cationic salt is 1:(1~3):(0.05~0.2):(0.5~2):(1~3);

[0012] Preferably, the photocurable resin is selected from at least one of TTA21, L-6206, L-6380H, and L-6605; preferably, the solvent is at least one of PMA, NMP, MDBE, and EMC.

[0013] Preferably, the stabilizer is a transition metal organometallic compound, preferably ferrocene and its derivatives, more preferably ferrocene, manganese ferrocene, or vinyl ferrocene;

[0014] Preferably, the organic precursor comprises an acid ester compound, preferably at least one of ethoxylated trimethylolpropane triacrylate (ETPTA) and trimethylolpropane triacrylate.

[0015] Preferably, the cationic salt is at least one of aluminum salt, potassium salt and sodium salt, and more preferably at least one of sodium perchlorate, potassium perchlorate and aluminum perchlorate, aluminum chloride, lithium chloride, sodium chloride, aluminum nitrate, sodium nitrate and sodium sulfate;

[0016] Preferably, the photocuring process involves irradiation with a 10-300W ultraviolet lamp for 30 seconds to 30 minutes.

[0017] Preferably, the resin slurry of the cationic salt further comprises at least one of a leveling agent, an adhesion promoter, and a defoamer;

[0018] The leveling agent is selected from at least one of BYK333, BYK358N, BYK306 and BYK378, and the amount added is 0.5% to 2% of the total mass of the slurry;

[0019] The adhesion promoter is selected from at least one of BYK4500, BYK4509, BYK4510, BYK4511 and BYK4512, and the amount added is 0.05 to 0.2% of the total mass of the slurry;

[0020] The defoamer is selected from at least one of BYK011, BYK012, BYK014, BYK018 and BUK019, and the amount added is 0.1 to 0.5% of the total mass of the slurry.

[0021] Preferably, the materials of the first transparent electrode layer and the second transparent electrode layer are independently selected from at least one of transparent conductive oxide and metal nanowires; the sheet resistance of the first transparent electrode layer and the second transparent electrode layer is 10 to 40 Ω / cm. 2 Visible light transmittance ≥75%.

[0022] Preferably, the encapsulation material is a thermosetting polyurethane-modified acrylic resin. The thermosetting polyurethane-modified acrylic resin is heat-cured using a curing agent selected from aliphatic isocyanates, preferably at least one selected from hexamethylene diisocyanate (HDI), isoflurane diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (HMDI), phenylenediamine diisocyanate (XDI), and tetramethyl-isophthalamide diisocyanate (TMXDI). Since electrochromic devices are susceptible to moisture corrosion during long-term use, this invention utilizes a thermosetting modified acrylic resin encapsulation around the device's periphery to effectively prevent water and oxygen from eroding the various film layers of the device from the sides, thereby improving the device's weather resistance and cycle stability.

[0023] Preferably, the electrochromic device has a stable cycle performance of ≥70,000 cycles; and the electrochromic device has a stable storage time of ≥2000 hours in an environment with a relative humidity of ≥85% and a temperature of 85℃.

[0024] On the other hand, the present invention provides a method for preparing the above-mentioned high-performance electrochromic device, wherein the method for preparing the gradient-crystallized electrochromic layer includes:

[0025] (1) An electrochromic layer is deposited on the surface of the first transparent electrode layer by magnetron sputtering.

[0026] (2) The electrochromic layer is treated with a rapid annealing process to obtain a crystalline electrochromic layer;

[0027] (3) The electrochromic layer is crystallized by plasma treatment to obtain a gradient crystallized electrochromic layer.

[0028] The fabrication process involved in this invention is simple, low-cost, and easy to promote. Therefore, the high-performance electrochromic device developed by this invention has broader application prospects.

[0029] Preferably, in step (1), the parameters of the magnetron sputtering method include: using tungsten, molybdenum, or titanium as the target material; using argon and oxygen as the sputtering gas; a total pressure of 0.5–2.0 Pa; an oxygen partial pressure of 0–50%; a distance of 10–20 cm between the target and the substrate; an initial substrate temperature of room temperature; and a DC power supply applied to the target of 30–150 W or a power density of 0.6–3.0 W / cm². 2 An electrochromic thin film of 500nm to 800nm ​​is deposited on the surface using a DC power supply.

[0030] Preferably, in step (2), the parameters of the rapid annealing process include: heating rate of 10-50℃ / min, 400-600℃, and holding time of 5s-15min.

[0031] Preferably, in step (3), the parameters of the plasma treatment include: high-purity argon atmosphere, pressure 10 Pa, power 50-180 W, and time 5-60 min.

[0032] Preferably, the encapsulation method of the encapsulation layer is as follows: a coagulating solution is prepared by weighing the curing agent and thermosetting polyurethane modified acrylic resin at a mass ratio of 1:(10-5), and then heat-treated to obtain the encapsulation layer.

[0033] Furthermore, preferably, the heat treatment temperature is 50–80°C and the time is 0.5–2 hours.

[0034] Furthermore, preferably, the encapsulation solution further comprises at least one of an antifoaming agent, a leveling agent, a slip agent, and an adhesion promoter.

[0035] Furthermore, preferably, the defoamer is selected from at least one of BYK011, BYK012 and BYK014, and the amount added is 0.1 to 0.5% of the total mass of the slurry.

[0036] Furthermore, preferably, the leveling agent is selected from at least one of BYK333, BYK358N, and BYK306, and the amount added is 0.2% to 1% of the total mass of the slurry.

[0037] Furthermore, preferably, the slip agent is selected from at least one of stearamide, erucamide, and glyceryl tristearate, and is added in an amount of 0.01 to 0.1% of the total mass of the slurry.

[0038] Furthermore, preferably, the adhesion promoter is selected from at least one of BYK4500, BYK4509 and BYK4510, and is added in an amount of 0.05 to 0.2% of the total mass of the slurry.

[0039] Beneficial effects:

[0040] 1. The present invention uses thermosetting modified acrylic resin to encapsulate the periphery of the device, which can effectively prevent water and oxygen from eroding the various film layers of the device from the side, thereby improving the weather resistance and cycle stability of the device.

[0041] 2. The present invention prepares a gradient crystallization electrochromic layer, which can not only improve the diffusion kinetics of ions in it, but also effectively avoid the irreversible defects caused by ions migrating to the electrode surface and recombinating with electrons under high voltage, thus significantly improving the coloring uniformity and response performance of the device. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the electrochromic device of the present invention. Detailed Implementation

[0043] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0044] In this disclosure, the structure of the high-performance electrochromic device is as follows: Figure 1 As shown, the device includes: a first transparent electrode, a gradient-crystalline electrochromic layer (or gradient-crystalline electrochromic layer), an electrolyte layer, a second transparent electrode, and a side encapsulation layer, stacked sequentially. It is important to note that this patent utilizes a gradient-crystalline electrochromic material. Compared to conventional crystalline or amorphous materials, this structure more readily absorbs moisture from the air. Therefore, a highly dense polymer encapsulation material is particularly necessary as the encapsulation layer.

[0045] Specifically, this invention uses a yellowing-resistant thermosetting aliphatic modified acrylic resin to encapsulate the periphery of the device, effectively preventing water and oxygen from eroding the various film layers of the device from the sides, thereby improving the device's weather resistance and cycle stability. Furthermore, by preparing a gradient-crystalline electrochromic layer, not only can the diffusion kinetics of ions within it be improved, but the irreversible defects caused by ions migrating to the electrode surface and recombinating with electrons under high voltage can also be effectively prevented, significantly improving the device's color uniformity and response performance.

[0046] In an optional embodiment, the gel electrolyte layer is a cation-conducting layer based on an organic resin, wherein the cation is Al. 3+ K + and Na + At least one of the following. Specifically, the gel electrolyte uses UV-curable resin as the base material, and adds appropriate amounts of solvent, cationic salt, stabilizer, reducing agent, defoamer, leveling agent, adhesion promoter and initiator, and then obtains a stable solution after thorough stirring and dissolution.

[0047] In this invention, an electrochromic layer is deposited on the electrode surface using magnetron sputtering, followed by rapid annealing to crystallize the electrochromic layer, and finally plasma treatment to obtain a gradient-crystallized electrochromic layer. The DC magnetron sputtering system used for deposition includes a deposition chamber, a sample inlet chamber, several target heads, a substrate, a DC current source, and a series of mechanical and vacuum pumps. The target heads are at a certain angle to the substrate and separated by a certain distance, and the DC power supply is connected to the target heads. The substrate is ultrasonically cleaned with acetone, anhydrous ethanol, and deionized water for 20 minutes each, and then dried with compressed air. A portion of the conductive substrate is covered with high-temperature tape as an electrode and fixed on the substrate tray. The substrate is placed in the sample inlet chamber, and the mechanical pump is turned on to pump the pressure to below 5 Pa. Then, the baffle valve is opened, and a vacuum (baseline vacuum) of 10 is introduced. -4 Splash chambers with Pa and below.

[0048] The specific sputtering deposition process is as follows: High-purity argon and oxygen are introduced into the sputtering chamber, with the purity of the argon and oxygen being 99.99% or higher. The total pressure and oxygen partial pressure within the chamber are controlled within the ranges of 0.5–2.0 Pa and 0–50%, respectively, with the oxygen partial pressure preferably being 0–25%. The vertical distance between the target and the substrate is controlled to be 10–20 cm, and the initial substrate temperature is room temperature. The DC power supply is turned on, and the power is controlled to be 30–200 W. The pre-sputtering time is 5–30 min, the sputtering time is 10–60 min, and the substrate temperature is room temperature. After sputtering, the substrate is removed after the substrate temperature has cooled to room temperature.

[0049] An example of preparing a gradient-crystallized electrochromic layer includes: selecting a transparent conductive glass substrate and continuously depositing an inorganic electrochromic layer on its surface. The layer is prepared by magnetron sputtering using tungsten, molybdenum, or titanium as the target material, with argon and oxygen as the sputtering gases, a total pressure of 0.5–2.0 Pa, an oxygen partial pressure of 0–50%, a target-substrate distance of 10–20 cm, an initial substrate temperature of room temperature, and a DC power supply of 30–150 W or a power density of 0.6–3.0 W / cm² applied to the target. 2An electrochromic layer of 500 nm to 800 nm was deposited on the surface using a DC power supply. The film was then subjected to rapid annealing at a heating rate of 10–50 °C / s, an annealing temperature of 450 °C, an annealing time of 5–15 min, and a vacuum level of 10. -4 ~10 -2 Pa. Subsequently, Ar plasma etching was performed in a high-purity argon atmosphere at a pressure of 10 Pa, a power of 50–180 W, and a time of 5–60 min.

[0050] Prepare the photocurable electrolyte precursor solution. (1) Add appropriate amounts of photocurable resin, solvent, ferrocene, ETPTA and cationic salt to the solution, controlling the mass ratio to be 1:(1-3):(0.05-0.2):(0.5-2):(1-3). Heat the mixed solution to 30-60℃ (e.g., 60℃) and stir thoroughly until the solute is completely dissolved. (3) Add (0.5-2)% leveling agent, (0.05-0.2)% adhesion promoter and (0.1-0.5)% defoamer to the above solution, and continue stirring the solution until it is clear and transparent. Deposit the above mixed solution onto the surface of the electrochromic layer using a spin coating process at a rotation speed of 1000-3000 rpm, resulting in a film thickness of 20-80 μm. Cover the top electrode after spin coating. Place the prepared device under a 100W UV lamp for uniform irradiation for 15s. After the device has cured, use an organic solvent to remove any excess organic matter from the device surface.

[0051] Aliphatic polyurethane-modified acrylic resin is prepared. A solution is prepared with a curing agent to resin ratio of 1:10 to 1:5, and (0.1-0.5)% defoamer, (0.2-0.1)% leveling agent, (0.01-0.1)% slip agent, and (0.05-0.2)% adhesion promoter are added by mass ratio. After the solution is stirred evenly, the prepared device is immersed in it for 30 seconds. After immersion, the device is dried at 50°C for 2-10 minutes. This completes the preparation process of the electrochromic device. The thermosetting polyurethane-modified acrylic resin used in this invention has better resistance to yellowing and water and oxygen barrier effects, thus meeting the application requirements of outdoor or other harsh environments. This patent proposes encapsulating the device with thermosetting resin material, resulting in a lower manufacturing process and cost, which is more beneficial for practical applications.

[0052] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0053] Example 1

[0054] (1) First, an inorganic electrochromic layer was continuously deposited on the surface of a transparent conductive glass substrate. Using magnetron sputtering with tungsten as the target and argon and oxygen as the sputtering gases, the total pressure was 0.5–2.0 Pa, the oxygen partial pressure was 15%, the distance between the target and the substrate was 15 cm, the initial substrate temperature was room temperature, and a 100 W DC power supply was applied to the target. A 600 nm electrochromic layer was deposited on the surface using a DC power supply. The film was then rapidly annealed at a heating rate of 20 °C / s, an annealing temperature of 450 °C, an annealing time of 10 min, and a vacuum degree of 10. -3 Pa. Subsequently, Ar plasma etching was performed in a high-purity argon atmosphere at a pressure of 10 Pa, a power of 120 W, and a time of 20 min. A gradient-crystalline electrochromic layer with a thickness of 400 nm in the crystalline portion, a thickness of 200 nm in the amorphous portion, and a roughness of 0.3 nm was obtained.

[0055] (2) Next, prepare the photocurable electrolyte precursor solution. Add appropriate amounts of photocurable resin, solvent, ferrocene, ETPTA, and lithium perchlorate in a propylene carbonate solution (1 mol / L) to the solution in a mass ratio of 1:2:0.1:1:2. Heat the mixed solution to 60°C and stir thoroughly until the solute is completely dissolved. Deposit the above mixed solution onto the surface of the electrochromic layer using a spin-coating process at a rotation speed of 2500 rpm and a film thickness of 60 μm. Cover the top electrode after spin-coating. Place the prepared device under a 100W UV lamp for uniform irradiation for 15 s. After the device has cured, use an organic solvent to remove excess organic matter from the device surface.

[0056] (3) Finally, prepare the aliphatic polyurethane modified acrylic resin. Prepare a solution with a curing agent to resin ratio of 1:7, and add 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) by mass ratio. After stirring the solution evenly, immerse the prepared device in it for 30 seconds. After immersion, dry the device at 50°C for 5 minutes. Repeat this process 3 times. This completes the preparation process of the electrochromic device. The basic structure of the device is as follows: Figure 1 As shown, it exhibits the best electrochromic performance, cycle stability, and environmental weather resistance.

[0057] Example 2

[0058] The fabrication process of the electrochromic device in Example 2 is the same as in Example 1, except that in step (1), an inorganic electrochromic layer is continuously deposited on the surface of a transparent conductive glass substrate. Using magnetron sputtering, tungsten metal is used as the target material, and argon and oxygen are used as the sputtering gases. The total pressure is 0.5-2.0 Pa, the oxygen partial pressure is 15%, the distance between the target and the substrate is 15 cm, the initial substrate temperature is room temperature, and a 100 W DC power supply is applied to the target. A 500 nm electrochromic layer film is deposited on the surface using a DC power supply. The film is then rapidly annealed at a heating rate of 20 °C / s, an annealing temperature of 450 °C, an annealing time of 10 min, and a vacuum degree of 10. -3 Pa. Subsequently, Ar plasma etching was performed in a high-purity argon atmosphere at a pressure of 10 Pa, a power of 120 W, and a time of 20 min. A gradient-crystalline electrochromic layer with a thickness of 300 nm in the crystalline portion, 200 nm in the amorphous portion, and a roughness of 0.3 nm was obtained.

[0059] Example 3

[0060] The fabrication process of the electrochromic device in Example 3 is the same as in Example 1, except that in step (1), an inorganic electrochromic layer is continuously deposited on the surface of a transparent conductive glass substrate. Using magnetron sputtering, tungsten metal is used as the target material, and argon and oxygen are used as the sputtering gases. The total pressure is 0.5-2.0 Pa, the oxygen partial pressure is 15%, the distance between the target and the substrate is 15 cm, the initial substrate temperature is room temperature, and the DC power applied to the target is 100 W. An 800 nm electrochromic layer film is deposited on the surface using a DC power supply. The film is then rapidly annealed at a heating rate of 20 °C / s, an annealing temperature of 450 °C, an annealing time of 10 min, and a vacuum degree of 10. -3 Pa. Subsequently, Ar plasma etching was performed in a high-purity argon atmosphere at a pressure of 10 Pa, a power of 120 W, and a time of 20 min. This yielded a crystalline region with a thickness of 600 nm, an amorphous region with a thickness of 200 nm, and a roughness of 0.3 nm.

[0061] Example 4

[0062] The fabrication process of the electrochromic device in Example 4 is the same as in Example 1, except that in step (1), an inorganic electrochromic layer is continuously deposited on the surface of a transparent conductive glass substrate. Using magnetron sputtering, tungsten metal is used as the target material, and argon and oxygen are used as the sputtering gases. The total pressure is 0.5-2.0 Pa, the oxygen partial pressure is 15%, the distance between the target and the substrate is 15 cm, the initial substrate temperature is room temperature, and the DC power applied to the target is 100 W. A 600 nm electrochromic layer film is deposited on the surface using a DC power supply. The film is then rapidly annealed at a heating rate of 20 °C / s, an annealing temperature of 450 °C, an annealing time of 10 min, and a vacuum degree of 10. -3Pa. Subsequently, Ar plasma etching was performed in a high-purity argon atmosphere at a pressure of 10 Pa, a power of 120 W, and a time of 5 min. A gradient-crystalline electrochromic layer with a thickness of 550 nm in the crystalline portion, a thickness of 50 nm in the amorphous portion, and a roughness of 0.5 nm was obtained.

[0063] Example 5

[0064] The fabrication process of the electrochromic device in Example 5 is the same as in Example 1, except that in step (1), an inorganic electrochromic layer is continuously deposited on the surface of a transparent conductive glass substrate. Using magnetron sputtering, tungsten metal is used as the target material, and argon and oxygen are used as the sputtering gases. The total pressure is 0.5-2.0 Pa, the oxygen partial pressure is 15%, the distance between the target and the substrate is 15 cm, the initial substrate temperature is room temperature, and the DC power applied to the target is 100 W. A 600 nm electrochromic layer film is deposited on the surface using DC power. The film is then rapidly annealed at a heating rate of 20 °C / s, an annealing temperature of 450 °C, an annealing time of 10 min, and a vacuum degree of 10⁻³ Pa. Ar plasma etching is then performed in a high-purity argon atmosphere at a pressure of 10 Pa, a power of 120 W, and a time of 5 min. A gradient-crystallized electrochromic layer with a crystalline thickness of 300 nm, an amorphous thickness of 300 nm, and a roughness of 0.2 nm is obtained.

[0065] Example 6

[0066] The preparation process of the electrochromic device in Example 6 is the same as in Example 1, except that in step (2), a photocurable electrolyte precursor solution is prepared. Appropriate amounts of photocurable resin, solvent, ferrocene, ETPTA, and cationic salt are added to the solution in a mass ratio of 1:2:0.1:1:2. The mixed solution is heated to 60°C and stirred thoroughly until the solute is completely dissolved. The above mixed solution is deposited onto the surface of the electrochromic layer using a spin-coating process at a rotation speed of 3000 rpm, controlling the film thickness to 20 μm. After spin-coating, the top electrode is covered. The prepared device is uniformly irradiated under a 100W UV lamp for 15 seconds. After the device has cured, excess organic matter on the device surface is removed using an organic solvent.

[0067] Example 7

[0068] The preparation process of the electrochromic device in Example 7 is the same as in Example 1, except that in step (2), a photocurable electrolyte precursor solution is prepared. Appropriate amounts of photocurable resin, solvent, ferrocene, ETPTA, and cationic salt are added to the solution in a mass ratio of 1:2:0.1:1:2. The mixed solution is heated to 60°C and stirred thoroughly until the solute is completely dissolved. The above mixed solution is deposited onto the surface of the electrochromic layer using a spin-coating process at a rotation speed of 1000 rpm, controlling the film thickness to 80 μm. After spin-coating, the top electrode is covered. The prepared device is uniformly irradiated under a 100W UV lamp for 15 seconds. After the device has cured, excess organic matter on the device surface is removed using an organic solvent.

[0069] Example 8

[0070] The preparation process of the electrochromic device in Example 8 is the same as in Example 1, except that in step (3), an aliphatic polyurethane modified acrylic resin is prepared. A solution is prepared according to a 1:10 ratio of curing agent to resin, and 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) are added by mass. After the solution is stirred evenly, the prepared device is immersed in it for 30 seconds. After immersion, the device is dried at 50°C for 5 minutes. This process is repeated 3 times. The preparation process of the electrochromic device is thus completed.

[0071] Example 9

[0072] The preparation process of the electrochromic device in Example 9 is the same as in Example 1, except that in step (3), an aliphatic polyurethane modified acrylic resin is prepared. A solution is prepared according to a 1:5 ratio of curing agent to resin, and 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) are added by mass. After the solution is stirred evenly, the prepared device is immersed in it for 30 seconds. After immersion, the device is dried at 50°C for 5 minutes. This process is repeated 3 times. The preparation process of the electrochromic device is thus completed.

[0073] Example 10

[0074] The preparation process of the electrochromic device in Example 10 is the same as in Example 1, except that in step (3), an aliphatic polyurethane modified acrylic resin is prepared. A solution is prepared according to a curing agent to resin ratio of 1:7, and 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) are added by mass ratio. After the solution is stirred evenly, the prepared device is immersed in it and kept for 30 seconds. After immersion, the device is dried at 50°C for 5 minutes. This process is repeated once. The preparation process of the electrochromic device is thus completed.

[0075] Example 11

[0076] The preparation process of the electrochromic device in Example 11 is the same as in Example 1, except that in step (3), an aliphatic polyurethane modified acrylic resin is prepared. A solution is prepared according to a curing agent to resin ratio of 1:7, and 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) are added by mass ratio. After the solution is stirred evenly, the prepared device is immersed in it and kept for 30 seconds. After immersion, the device is dried at 50°C for 5 minutes. This process is repeated 5 times. The preparation process of the electrochromic device is thus completed.

[0077] Example 12

[0078] The preparation process of the electrochromic device in Example 12 is the same as in Example 1, except that in step (3), aliphatic polyurethane modified acrylic resin is prepared. A solution is prepared according to a curing agent to resin ratio of 1:7, and 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) are added by mass ratio. After the solution is stirred evenly, the prepared device is immersed in it and kept for 5 seconds. After immersion, the device is dried at 50°C for 5 minutes. This process is repeated 3 times. The preparation process of the electrochromic device is thus completed.

[0079] Example 13

[0080] The preparation process of the electrochromic device in Example 13 is the same as in Example 1, except that in step (3), an aliphatic polyurethane modified acrylic resin is prepared. A solution is prepared according to a curing agent to resin ratio of 1:7, and 0.2% defoamer (specifically BYK012), 0.1% leveling agent (specifically BYK358N), 0.05% slip agent (specifically erucamide), and 0.1% adhesion promoter (specifically BYK4510) are added by mass ratio. After the solution is stirred evenly, the prepared device is immersed in it and kept for 60 seconds. After immersion, the device is dried at 50°C for 5 minutes. This process is repeated 3 times. The preparation process of the electrochromic device is thus completed.

[0081] Comparative Example 1

[0082] The fabrication process of the electrochromic device in Comparative Example 1 is the same as in Example 1, except that in step (3), a transparent conductive glass substrate is selected, and an inorganic electrochromic layer is continuously deposited on its surface. A magnetron sputtering method is used, with tungsten metal as the target material, argon and oxygen as the sputtering gases, a total pressure of 0.5–2.0 Pa, an oxygen partial pressure of 15%, a target-to-substrate distance of 15 cm, an initial substrate temperature of room temperature, and a DC power of 100 W applied to the target material. A 600 nm electrochromic layer film is deposited on the surface using a DC power supply. That is, Comparative Example 1 does not involve annealing or plasma treatment.

[0083] Comparative Example 2

[0084] The fabrication process of the electrochromic device in Comparative Example 2 is the same as that in Example 1, except that in step (3), a transparent conductive glass substrate is selected, and an inorganic electrochromic layer is continuously deposited on its surface. A magnetron sputtering method is used, with tungsten metal as the target material, argon and oxygen as the sputtering gases, a total pressure of 0.5–2.0 Pa, an oxygen partial pressure of 15%, a target-to-substrate distance of 15 cm, an initial substrate temperature of room temperature, and a DC power of 100 W applied to the target material. A 600 nm electrochromic layer film is deposited on the surface using a DC power supply. The film is then rapidly annealed at a heating rate of 20 °C / s, an annealing temperature of 450 °C, an annealing time of 10 min, and a vacuum degree of 10. -3 Pa. That is, there was no plasma treatment in Comparative Example 2.

[0085] Table 1 shows:

[0086]

[0087]

[0088] Table 2 shows:

[0089] Loop count / 10,000 times High temperature and high humidity storage time / h Example 1 110,000 times 5000h Example 2 90,000 times 3500h Example 3 100,000 times 4000h Example 4 70,000 times 4500h Example 5 100,000 times 2600h Example 6 101,000 times 3700h Example 7 72,000 times 2000h Example 8 83,000 times 2700h Example 9 87,000 times 2600h Example 10 72,000 times 2000h Example 11 109,000 times 4800h Example 12 92,000 times 3600h Example 13 77,000 times 4100h Comparative Example 1 36,000 times 3600h Comparative Example 2 23,000 times 3800h

[0090] The term "cycle count" refers to the number of times the electrochromic device effectively reduces the adjustment amplitude at 630nm by less than 10% during the cycling process, preferably 70,000 to 110,000 cycles. The term "high temperature and high humidity storage time" refers to the time the electrochromic device remains stable when stored in an environment with relative humidity ≥85% and temperature 85℃, preferably 2000-5000 hours.

Claims

1. A method for fabricating a high-performance electrochromic device, characterized in that, The high-performance electrochromic device includes: a multilayered structure unit consisting of a first transparent electrode layer, a gradient-crystallized electrochromic layer, a gel electrolyte layer, and a second transparent electrode layer stacked sequentially, and an encapsulation layer disposed on the side of the multilayered structure unit. The method for preparing the gradient-crystallized electrochromic layer includes: (1) An electrochromic layer is deposited on the surface of the first transparent electrode layer by magnetron sputtering; (2) The electrochromic layer is treated with a rapid annealing process to obtain a crystalline electrochromic layer; (3) The electrochromic layer is crystallized by plasma treatment to obtain a gradient crystallized electrochromic layer.

2. The preparation method according to claim 1, characterized in that, The gradient-crystallized electrochromic layer includes an inorganic crystalline layer and an inorganic amorphous layer distributed on the surface of the first transparent electrode layer. The material of the gradient-crystallized electrochromic layer is at least one of WO3, MoO3 and TiO2. The surface roughness of the inorganic amorphous layer in the gradient-crystallized electrochromic layer is ≤0.5 nm.

3. The preparation method according to claim 2, characterized in that, The thickness of the inorganic crystalline layer in the gradient-crystallized electrochromic layer is 200–600 nm, and the thickness of the inorganic amorphous layer is 50–300 nm; the total thickness of the gradient-crystallized electrochromic layer is 500–800 nm.

4. The preparation method according to claim 1, characterized in that, The gel electrolyte layer is obtained by photocuring a resin slurry containing cationic salts. The composition of the cation salt resin slurry includes: photocurable resin, solvent, stabilizer, organic precursor and cation salt; the mass ratio of the photocurable resin, solvent, stabilizer, organic precursor and cation salt is 1:(1~3):(0.05~0.2):(0.5~2):(1~3); The photocurable resin is selected from at least one of TTA21, L-6206, L-6380H, and L-6605. The solvent is at least one of PMA, NMP, MDBE and EMC; The stabilizer is a transition metal organometallic compound; The organic precursor includes acid ester compounds; The cationic salt is at least one of aluminum salt, potassium salt and sodium salt; The photocuring process involves irradiating the light with a 10-300W ultraviolet lamp for 30 seconds to 30 minutes.

5. The preparation method according to claim 4, characterized in that, The organic precursor includes at least one of ethoxylated trimethylolpropane triacrylate (ETPTA) and trimethylolpropane triacrylate. The cation salt is sodium perchlorate, potassium perchlorate, or aluminum perchlorate. 、 At least one of aluminum chloride, lithium chloride, sodium chloride, aluminum nitrate, sodium nitrate, and sodium sulfate.

6. The preparation method according to claim 4, characterized in that, The cation salt resin slurry also contains at least one of a leveling agent, an adhesion promoter, and a defoamer. The leveling agent is selected from at least one of BYK333, BYK358N, BYK306 and BYK378, and the amount added is 0.5% to 2% of the total mass of the slurry; The adhesion promoter is selected from at least one of BYK4500, BYK4509, BYK4510, BYK4511 and BYK4512, and is added in an amount of 0.05 to 0.2% of the total mass of the slurry. The defoamer is selected from at least one of BYK011, BYK012, BYK014, BYK018 and BUK019, and the amount added is 0.1 to 0.5% of the total mass of the slurry.

7. The preparation method according to claim 1, characterized in that, The materials of the first and second transparent electrode layers are independently selected from at least one of transparent conductive oxides and metal nanowires; the sheet resistance of the first and second transparent electrode layers is 10–40 Ω / cm. 2 Visible light transmittance ≥75%.

8. The preparation method according to claim 1, characterized in that, The encapsulation layer is made of thermosetting polyurethane modified acrylic resin; the thermosetting polyurethane modified acrylic resin is subjected to heat curing treatment, and the curing agent used is selected from aliphatic isocyanates.

9. The preparation method according to claim 8, characterized in that, The curing agent is selected from at least one of hexamethylene diisocyanate (HDI), isoflurone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (HMDI), phenylenediamine diisocyanate (XDI), and tetramethylisophthalimethylene diisocyanate (TMXDI).

10. The preparation method according to claim 1, characterized in that, The high-performance electrochromic device has a stable cycle performance of ≥70,000 cycles; the high-performance electrochromic device can be stably stored for ≥2000 hours in an environment with relative humidity ≥85% and temperature 85℃.

11. The preparation method according to claim 8, characterized in that, In step (1), the parameters of the magnetron sputtering method include: using tungsten, molybdenum, or titanium as the target material; using argon and oxygen as the sputtering gas; a total pressure of 0.5–2.0 Pa; an oxygen partial pressure of 0–50%; a distance of 10–20 cm between the target and the substrate; an initial substrate temperature of room temperature; and a DC power supply applied to the target of 30–150 W or a power density of 0.6–3.0 W / cm². 2 An electrochromic thin film of 500 nm to 800 nm was deposited on the surface using a DC power supply; In step (2), the parameters of the rapid annealing process include: heating rate of 10-50℃ / min, heating to 400-600℃, and holding for 5s-15min; In step (3), the parameters of the plasma treatment include: high-purity argon atmosphere, pressure 10 Pa, power 50-180 W, and time 5-60 min; The encapsulation method of the encapsulation layer is as follows: a coagulant and thermosetting polyurethane modified acrylic resin are weighed at a mass ratio of 1:(10-5) to prepare an encapsulation solution, and then the encapsulation layer is obtained by heat treatment. The heat treatment is performed at a temperature of 50–80°C for a time of 0.5–2 hours. The encapsulation solution also contains at least one of the following: defoamer, leveling agent, slip agent, and adhesion promoter; The defoamer is selected from at least one of BYK011, BYK012, and BYK014, and the amount added is 0.1% to 0.5% of the total mass of the encapsulation solution. The leveling agent is selected from at least one of BYK333, BYK358N, and BYK306, and the amount added is 0.2% to 11% of the total mass of the encapsulation solution. The slip agent is selected from at least one of stearamide, erucamide, and glyceryl tristearate, and is added in an amount of 0.01 to 0.1% of the total mass of the encapsulation solution. The adhesion promoter is selected from at least one of BYK4500, BYK4509 and BYK4510, and the amount added is 0.05 to 0.2% of the total mass of the encapsulation solution.

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