Preparation method of metal reflecting layer and application of metal reflecting layer in electrochromism field

Abstract

The invention relates to a preparation method of a metal reflecting layer and application of the metal reflecting layer in the field of electrochromism, and the preparation method comprises the following steps: firstly, preparing a sensitizing solution by using hydrochloric acid as a solvent and stannous chloride as a solute so as to facilitate deposition of a metal film on any substrate; deionized water is used as a solvent, nitrate is used as a solute, and deposition precursor liquid is prepared; deionized water is used as a solvent, glucose is used as a solute, and a reducing solution is prepared. The method is compatible with substrates in any shapes, the hydrophilicity of the substrates is enhanced through the sensitizing solution, the low-temperature reaction is combined, uniform deposition on irregular substrates of a plane, a curved surface, a three-dimensional structure and the like is achieved, the reflecting layer can cover a complex surface, and the limitation that only a two-dimensional plane is limited in the traditional technology is broken through.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal coatings, and relates to a metal deposition technology using a chemical method, in particular to a method for preparing a metal reflective layer and its application in the field of electrochromism. Background Art

[0002] Electrochromism is a special optical phenomenon that refers to the reversible color change of certain materials under the action of an external electric field. It can adjust the absorption and reflection characteristics of the material to light of different wavelengths, causing its color to switch between different states.

[0003] Reflective electrochromic devices use electrochromic materials to change their reflectivity under the influence of an electric field to achieve color change. Their operating principle is based on the electrochemical redox reaction or ion insertion / deintercalation process of the electrochromic material. Dynamic color changes are achieved by adjusting the reflectivity of the electrochromic material. Currently, the electrochromic material itself can be directly used to reflect or absorb light in certain wavelengths. Alternatively, a metal reflective layer can be added between the electrochromic layer and the electrolyte layer, attached to the electrochromic layer, serving as both a reflective layer and a current collector. Dynamic changes in transparency are achieved by changing the transmittance of the electrochromic material, utilizing the low transmittance of the electrochromic layer to achieve light absorption and absorption, while the metal layer achieves light reflection. Reflective electrochromic devices show excellent application prospects in thermal management, information display, and other fields. If reflective electrochromic devices are integrated with building envelopes, they can more intelligently regulate heat conduction and radiation between the building and the outside world, thereby using light regulation to achieve cooling and heating within the building.

[0004] Reflective electrochromic devices are composed of five parts: a transparent conductive substrate layer, an electrochromic layer, a reflective layer, an electrolyte layer, and a counter electrode layer. Currently, most conductive substrates are made of transparent conductive oxides coated on glass or flexible polymer films. Indium resources are scarce, resulting in high costs. They are also easily degraded or passivated under high temperatures or mechanical stress, and the preparation process is complex, resulting in high costs and limited application in flexible electronic devices. The reflective layer mainly provides a reflective effect after light passes through the electrochromic layer. It plays a vital role in reflective electrochromic devices. In the preparation process of some currently reported large-area reflective layers, achieving uniform deposition and distribution of materials is a challenge. Reflective electrochromic devices usually require a multilayer film structure (such as a reflective layer, an electrochromic layer, an electrolyte layer, etc.). The interface quality between the layers and the uniformity of the film thickness are crucial to the performance of the device. However, current fabrication processes struggle to precisely control these parameters, leading to problems such as short circuits between film layers. For example, commonly used fabrication methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD) are prone to uneven thickness, pinholes, and cracks when fabricating thin films on large-area substrates, impacting the performance and quality of the reflective layer. Some fabrication processes can achieve good results on small-area samples, but face challenges with process parameter adjustment and equipment compatibility when producing on a large scale. This results in poor scalability and makes it difficult to meet the demand for large-area reflective layers in practical applications. Furthermore, these methods cannot fabricate metal reflective layers on complex or curved surfaces, limiting the majority of applications for reflective electrochromic devices. Furthermore, in terms of material costs, high-performance reflective layer materials such as precious metals and transparent conductive materials are expensive, and the development of new materials requires significant R&D investment. In terms of equipment costs, high-precision fabrication equipment is expensive and has high maintenance costs, making large-area fabrication equipment scarce. The reflective layer and current collector layer are responsible for both reflecting light and conducting electricity. As a crucial component of electrochromic devices, the conductive substrate's resistance is directly related to the efficiency of electron transmission within the device, which in turn influences key performance characteristics such as color change speed, contrast, energy consumption, and cycling stability. Existing methods for processing metal reflective layers require complex procedures, resulting in high production costs. Furthermore, these methods are limited to two-dimensional planar substrates, making them unsuitable for application in three-dimensional or complex electrochromic devices. Therefore, there is an urgent need to reduce the production cost and process complexity of electrochromic devices. New low-temperature solution processing methods for metal reflective layers are urgently needed. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, provide a method for preparing a metal reflective layer and its application in the field of electrochromism, and provide a new idea for preparing electrochromic devices with high reflectivity.

[0006] The present invention solves the technical problem by adopting the following technical solutions:

[0007] A method for preparing a metal reflective layer comprises the following steps:

[0008] S1. Substrate pretreatment: Wash the substrate with water, acetone, and isopropanol in an ultrasonic water bath, and then dry.

[0009] S2. Preparation of a deposition precursor solution: adding 2 wt.% to 10 wt.% of silver nitrate to deionized water to form a silver nitrate solution, and ultrasonically dispersing the solution until the silver nitrate is completely dissolved to obtain a deposition precursor solution;

[0010] S3. Preparation of silver ammonia complex solution: adding 20 wt.% to 28 wt.% ammonia water dropwise to the deposition precursor solution with stirring until the silver nitrate solution first turns brown and turbid and then gradually becomes clear, thereby forming a silver ammonia complex solution;

[0011] S4. Preparation of a sedimentation reduction solution: adding 5 wt.% to 10 wt.% of glucose to deionized water, and ultrasonically dispersing until the glucose is completely dissolved to obtain a sedimentation reduction solution;

[0012] S5. Preparation of sensitizing solution: add 0.01-0.1 mol of stannous chloride to hydrochloric acid, then add deionized water, and ultrasonically disperse until the stannous chloride is completely dissolved to obtain a sensitizing solution;

[0013] S6. Substrate sensitization: The pretreated substrate is subjected to secondary treatment, then immersed in the sensitizing solution for 1-3 minutes, washed, and dried;

[0014] S7. Preparation of a metal reflective layer: Mix the deposition reduction solution described in step S4 with the silver ammonia complex solution described in step S3 to form a mixed solution, immerse the sensitized substrate in the mixed solution, react in a water bath at 40-90° C. for 5-10 minutes, remove the substrate, wash it, and dry it to form a metal reflective layer.

[0015] Moreover, in step S1, the washing time is 13-18 minutes; and the drying time is 60-80°C.

[0016] Furthermore, in step S1 , the substrate is a transparent carrier of any shape, including a flat or curved structure; the material of the substrate includes glass, polyethylene terephthalate, or acrylic board.

[0017] Moreover, in step S5, the solvent is a mixed solution of hydrochloric acid and deionized water, and the volume ratio of hydrochloric acid to deionized water is 1:4.

[0018] Furthermore, in step S6, the secondary treatment is: adhering a high temperature resistant tape to one side of the substrate pre-treated in step S1.

[0019] Moreover, the high temperature resistant tape is a polyimide tape.

[0020] Furthermore, in step S6, the drying temperature is 60-80°C.

[0021] Moreover, in step S7, the mass ratio of silver nitrate to glucose solute in the mixed solution is 0.5-2:1-8.

[0022] Furthermore, in step S7, the drying temperature is 60-80°C.

[0023] A method for preparing a metal reflective layer and application of the prepared metal reflective layer in an electrochromic device.

[0024] The advantages and positive effects of the present invention are:

[0025] 1. The present invention obtains a highly efficient metal reflective layer for electrochromic devices by adopting simple solution deposition to form films. Compared with the prior art, the metal reflective layer formed by the present invention does not require the use of high-vacuum precision equipment and high-purity target materials, and only requires low-temperature water bath heating at 40-80°C. The product also has excellent visible light reflection ability, thereby greatly reducing the production cost of the reflective layer of the electrochromic device while ensuring product quality.

[0026] 2. The present invention can deposit a high-reflectivity electrochromic device reflective layer on an irregular substrate of any shape through a low-temperature solution deposition method. Compared with traditional methods, the method of the present invention does not require a complex production environment to prepare an electrochromic device reflective layer with excellent performance.

[0027] 3. The research ideas of the present invention are clear and rigorous, with strong repeatability. It has great reference value for the design invention of the processing method of the metal reflective layer for electrochromic devices. The metal reflective layer material designed by the present invention has good stability and meets the application requirements of electrochromic devices.

[0028] 4. The present invention is compatible with substrates of any shape. By enhancing the hydrophilicity of the substrate through a sensitizing solution (stannous chloride) and combining it with a low-temperature reaction, it can achieve uniform deposition on irregular substrates such as flat surfaces, curved surfaces, and three-dimensional structures. The reflective layer can cover complex surfaces, breaking through the limitation of traditional technology that is limited to two-dimensional planes.

[0029] 5. The metal reflective layer prepared by the present invention has high visible light reflectivity and can be applied to substrates of regular or irregular shapes to meet the needs of different application scenarios. It can be applied to the reflective layer and current collector in electrochromic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a digital photograph of the metal reflective layer and electrochromic layer prepared on an irregular substrate according to the present invention.

[0031] Figure 2 This is a digital photo of the color change of the electrochromic electrode prepared by using a metal reflective layer and an electrochromic layer on a substrate according to the present invention.

[0032] Figure 3 The figures are dynamic reflectivity diagrams of the electrochromic reflective layer prepared at different temperatures of the present invention after being combined with the PPy electrochromic material.

[0033] Figure 4 This is a dynamic reflectivity diagram of the electrochromic reflective layer prepared under different silver nitrate conditions of the present invention after being combined with the PPy electrochromic material.

[0034] Figure 5 This is a comparison of the contact angles between the PET substrate and the solution with and without the sensitizer of the present invention.

[0035] Figure 6 This is a picture of the metal reflective layer Ag / PET prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the scope of protection of the present invention cannot be limited thereto.

[0037] A method for preparing a metal reflective layer, the present invention provides the following technical solution: First, a sensitizing solution is prepared using hydrochloric acid as a solvent and stannous chloride as a solute to facilitate the deposition of a metal thin film on any substrate. A precursor solution is prepared: (1) Deionized water is used as a solvent and nitrate is used as a solute to prepare a deposition precursor solution 1. (2) Deionized water is used as a solvent and glucose is used as a solute to prepare a reducing solution (precursor solution 2).

[0038] The present invention generates a stable metal reflective layer by mixing a precursor liquid with a reducing solution on a sensitized substrate. The following preferred technical solution for preparing the reflective layer of an electrochromic device includes the following steps:

[0039] Step 1: Substrate Cleaning: One of the keys to high-quality metal films is substrate cleaning. The substrate is cleaned in an ultrasonic bath for 15 minutes each with water, acetone, and isopropyl alcohol. It is then dried in an oven at 60°C.

[0040] In the present invention, there is no limitation on the carrier for depositing the metal reflective layer. Preferably, the substrate includes a transparent carrier of any shape such as glass, polyethylene terephthalate (PET), acrylic plate, etc.

[0041] Step 2, preparation of a deposition precursor solution: taking a certain amount of deionized water, adding 2 wt.%-10 wt.% of silver nitrate therein, and ultrasonically dispersing until the silver nitrate is completely dissolved to obtain a deposition precursor solution.

[0042] Step 3, preparation of deposition reduction solution: taking a certain amount of deionized water, adding 5wt.%-10wt.% of glucose therein, and ultrasonically dispersing until the glucose is completely dissolved to obtain deposition reduction solution.

[0043] Step 4, preparation of sensitizing solution: take a certain amount of hydrochloric acid, add 0.01-0.1 mol of stannous chloride into it, and ultrasonically disperse until the stannous chloride is completely dissolved to obtain a sensitizing solution.

[0044] Step 5: First, use a high-temperature resistant tape to stick the cleaned substrate to one side of the substrate to prevent the metal film from being deposited on both sides of the substrate and affecting its use. Preferably, the high-temperature resistant tape is a polyimide tape.

[0045] Step 6: Soak the tape-attached substrate in the sensitizing solution prepared in step 4 for 1-3 minutes, then rinse with plenty of deionized water. Then, dry in an oven at 60°C.

[0046] Step 7: 28 wt.% ammoniacal liquor is dropwise added to the silver nitrate solution prepared in step 2, while stirring the solution until the silver nitrate solution first turns brown and turbid and then gradually clarifies to form a silver ammonia complex solution. Preferably, the silver ammonia complex solution needs to be prepared on demand and is preferably used within 10 minutes after preparation.

[0047] Step 8: Evenly mix the solutions prepared in step 3 and step 8, place the substrate dried in step 6 in the mixed solution, and heat the entire system in a water bath at 40-90° C. for 5-10 minutes.

[0048] Step 9: The reacted substrate was removed from the solution, rinsed with a large amount of deionized water, and then dried in an oven at 60°C.

[0049] Example 1

[0050] A method for preparing a metal reflective layer Ag / PET is provided in this embodiment. The method includes the following steps:

[0051] First, a 2.5×5 cm PET substrate was washed in an ultrasonic bath with water, acetone, and isopropanol for 15 minutes, respectively. Subsequently, it was dried in an oven at 60°C. Two 100 ml beakers, A and B, were used: 3.5 g of silver nitrate was weighed into beaker A and 7 g of glucose was weighed into beaker B. 70 mL of deionized water was added to each beaker A and B, respectively, and ultrasonically dispersed. 0.113 g of stannous chloride dihydrate was weighed into beaker C, and 10 mL of concentrated hydrochloric acid was slowly added. Stirring was performed until the stannous chloride dihydrate was completely dissolved. Then, 40 mL of deionized water was slowly added to beaker C, stirring continuously, to prepare a 0.01 M stannous chloride sensitizing solution. The prepared PET substrate was sensitized in the sensitizing solution for 2 minutes, removed, rinsed with copious amounts of deionized water, and dried. 28 wt.% ammonia water was added dropwise to beaker A, stirring constantly, until the silver nitrate solution first turned brown and turbid and then gradually clarified, forming a silver-ammine complex solution. Mix the solutions in beakers A and B, and place the sensitized PET substrate into the mixed solution. Heat it in a water bath at 70°C for 10 minutes. After the reaction is complete, remove the PET, rinse it with deionized water, and dry it to obtain a metal reflective layer Ag / PET. Figure 6 shown.

[0052] Example 2

[0053] A method for preparing a metal reflective layer Ag / glass is provided. This embodiment provides a method for preparing the metal reflective layer using a three-dimensional cylindrical glass bottle substrate, comprising the following steps:

[0054] First, a three-dimensional cylindrical glass bottle substrate was washed in an ultrasonic bath with water, acetone, and isopropanol for 15 minutes, respectively. Subsequently, it was dried in an oven at 60°C. Two 100ml beakers, A and B, were used: 3.5g of silver nitrate was weighed into beaker A and 7g of glucose was weighed into beaker B. 70ml of deionized water was added to each beaker A and B, respectively, and ultrasonically dispersed. 0.113g of stannous chloride dihydrate was weighed into beaker C, and 10ml of concentrated hydrochloric acid was slowly added. Stirring was carried out until the stannous chloride dihydrate was completely dissolved. Then, 40ml of deionized water was slowly added to beaker C, stirring continuously, to prepare a 0.01M stannous chloride sensitizing solution. The prepared glass bottle substrate was sensitized in the sensitizing solution for 2 minutes, removed, rinsed with copious amounts of deionized water, and dried. 28wt.% ammonia water was added dropwise to beaker A, stirring constantly, until the silver nitrate solution first turned brown and turbid and then gradually clarified, forming a silver-ammine complex solution. Mix the solutions in beakers A and B, and place the sensitized glass bottle substrate into the mixed solution. Heat it in a water bath at 70°C for 10 minutes. After the reaction is complete, remove the PET, rinse it with deionized water, and dry it to obtain the metal reflective layer Ag / glass. Figure 1 As shown in (a), the Ag reflective layer is uniformly deposited on the three-dimensional cylindrical glass bottle substrate.

[0055] Example 3

[0056] A method for preparing a metal reflective layer Ag / acrylic is provided. This embodiment provides a method for preparing the same using a hemispherical acrylic substrate, comprising the following steps:

[0057] First, wash a hemispherical acrylic substrate in an ultrasonic bath for 15 minutes each with water, acetone, and isopropanol. Then, dry it in an oven at 60°C. Prepare two 100ml beakers, A and B: weigh 3.5g of silver nitrate into beaker A and 7g of glucose into beaker B. Add 70ml of deionized water to each beaker, respectively, and ultrasonically disperse the mixture. Weigh 0.113g of stannous chloride dihydrate into beaker C, slowly add 10ml of concentrated hydrochloric acid, and stir slowly until the stannous chloride dihydrate is completely dissolved. Then, slowly add 40ml of deionized water to beaker C, stirring continuously, to prepare a 0.01M stannous chloride sensitizing solution. Sensitize the prepared acrylic substrate in the sensitizing solution for 2 minutes, remove it, rinse it with plenty of deionized water, and dry it. Add 28wt.% ammonia water dropwise to beaker A, stirring constantly, until the silver nitrate solution turns brown and turbid and then gradually clarifies, forming a silver-ammine complex solution. Mix the solutions in beakers A and B, and place the sensitized acrylic substrate into the mixed solution. Heat in a water bath at 70°C for 10 minutes. After the reaction is complete, remove the hemispherical acrylic, rinse with deionized water, and dry to obtain a metal reflective layer Ag / acrylic. Figure 1 As shown in (b), the Ag reflective layer is uniformly deposited on the hemispherical acrylic substrate.

[0058] Example 4

[0059] A method for preparing a metal reflective layer Ag / PPy / acrylic. This embodiment provides a method for preparing a PPy / hemispherical acrylic composite substrate, comprising the following steps:

[0060] First, a hemispherical acrylic substrate was washed in an ultrasonic bath for 15 minutes with water, acetone, and isopropanol, respectively. Subsequently, it was dried in an oven at 60°C to uniformly deposit PPy on the hemispherical acrylic substrate. Next, two 100ml beakers, A and B, were placed: 3.5g of silver nitrate was weighed into beaker A and 7g of glucose into beaker B. 70ml of deionized water was added to each beaker A and B, respectively, and ultrasonically dispersed. 0.113g of stannous chloride dihydrate was weighed into beaker C, and 10ml of concentrated hydrochloric acid was slowly added. Stirring was carried out until the stannous chloride dihydrate was completely dissolved. Then, 40ml of deionized water was slowly added to beaker C, stirring continuously, to prepare a 0.01M stannous chloride sensitizing solution. The prepared acrylic substrate was placed in the sensitizing solution for 2 minutes, removed, rinsed with plenty of deionized water, and dried. Add 28 wt.% ammonia water dropwise to beaker A, stirring constantly, until the silver nitrate solution turns brown and turbid before gradually clarifying, forming a silver-ammine complex solution. Combine the solutions in beakers A and B, place the sensitized acrylic substrate in the mixed solution, and heat in a waterbath at 70°C for 10 minutes. Once the reaction is complete, remove the acrylic hemisphere, rinse with deionized water, and dry to obtain a metallic reflective layer of Ag / PPy / acrylic.

[0061] like Figure 2 As shown, the application of metal reflective layer in the field of electrochromism is demonstrated. Figure 2 (a) is the state of not changing color, Figure 2 (b) is the color-changed state.

[0062] Example 5

[0063] A method for preparing a metal reflective layer Ag / PPy / PET is provided in this embodiment using a PPy / PET composite substrate at a water bath temperature of 30°C, comprising the following steps:

[0064] First, a 2.5×5 cm PET substrate was washed in an ultrasonic bath for 15 minutes with water, acetone, and isopropanol, respectively. Subsequently, the substrate was dried in an oven at 60°C to uniformly coat the PET surface with PPy. Next, two 100 mL beakers (A and B) were prepared: 3.5 g of silver nitrate was weighed into beaker A, and 7 g of glucose was weighed into beaker B. 70 mL of deionized water was added to each beaker A and B, respectively, and ultrasonically dispersed. 0.113 g of stannous chloride dihydrate was weighed into beaker C, and 10 mL of concentrated hydrochloric acid was slowly added. The solution was stirred slowly until the stannous chloride dihydrate was completely dissolved. 40 mL of deionized water was then slowly added to beaker C, stirring continuously, to prepare a 0.01 M stannous chloride sensitizing solution. The prepared PPy / PET substrate was sensitized in the sensitizing solution for 2 minutes. The substrate was then removed, rinsed with copious amounts of deionized water, and dried. Add 28 wt.% ammonia water dropwise to beaker A, stirring constantly, until the silver nitrate solution turns brown and turbid before gradually clarifying, forming a silver-ammine complex solution. Combine the solutions in beakers A and B, place the sensitized PET substrate in the mixed solution, and heat in a waterbath at 30°C for 10 minutes. Once the reaction is complete, remove the PET, rinse with deionized water, and dry to obtain a metallic reflective layer, Ag / PPy / PET.

[0065] Example 6

[0066] This embodiment provides methods for preparing the Ag / PPy / PET metal reflective layer at water bath temperatures of 40°C, 50°C, 60°C, 70°C, and 80°C, respectively. The rest is the same as in Example 5.

[0067] like Figure 3 As shown in the figure, the reflectivity of the electrochromic electrode using the metal reflective layer in the visible light band is shown. It can be seen that at 70°C, the optical contrast of the electrochromic electrode using the metal reflective layer in the visible light band is the highest, which is 40.8%. Figure 3 (a) is at a water bath temperature of 30°C, Figure 3 (b) is at 40℃ water bath temperature, Figure 3 (c) is at a water bath temperature of 50°C, Figure 3 (d) is at 60℃ water bath temperature, Figure 3 (e) is at 70℃ water bath temperature, Figure 3 (f) is at 80°C water bath temperature.

[0068] Example 7

[0069] A method for preparing a metal reflective layer Ag / PPy / PET is provided in this embodiment using 2 wt.% silver nitrate, comprising the following steps:

[0070] First, a 2.5×5 cm PET substrate was washed in an ultrasonic bath for 15 min each with water, acetone, and isopropanol. Subsequently, the substrate was dried in an oven at 60°C to uniformly deposit PPy on the PET surface. Next, two 100 ml beakers (A and B) were prepared: 70 ml of deionized water was added to beakers A and B, respectively. To beaker A, 2 wt.% silver nitrate and an appropriate amount of glucose (at a silver nitrate:glucose ratio of 1:2) were added, and ultrasonic dispersion was performed. 0.113 g of stannous chloride dihydrate was weighed and placed in beaker C. 10 ml of concentrated hydrochloric acid was slowly added, stirring slowly until the stannous chloride dihydrate was completely dissolved. 40 ml of deionized water was then slowly added to beaker C, stirring continuously, to prepare a 0.01 M stannous chloride sensitizing solution. The prepared PPy / PET substrate was sensitized in the solution for 2 min. The substrate was then removed, rinsed with copious amounts of deionized water, and dried. Add 28 wt.% ammonia water dropwise to beaker A, stirring constantly, until the silver nitrate solution turns brown and turbid before gradually clarifying, forming a silver-ammine complex solution. Combine the solutions in beakers A and B, place the sensitized PET substrate in the mixed solution, and heat in a waterbath at 70°C for 10 minutes. Once the reaction is complete, remove the PET, rinse with deionized water, and dry to obtain a metallic reflective layer, Ag / PPy / PET.

[0071] Example 8

[0072] This embodiment provides methods for preparing Ag / PPy / PET metal reflective layers using 3 wt.%, 4 wt.%, 5 wt.%, and 6 wt.% silver nitrate, respectively. The rest is the same as in Example 7.

[0073] like Figure 4 As shown in the figure, the reflectivity of the electrochromic electrode using the metal reflective layer in the visible light band is shown. It can be seen that at a silver nitrate concentration of 4wt.%, the optical contrast of the electrochromic electrode using the metal reflective layer in the visible light band is the highest, at 46.5%. Figure 4 (a) 2 wt.% silver nitrate, Figure 4 (b) is 3 wt.% silver nitrate, Figure 4 (c) is 4 wt.% silver nitrate, Figure 4 (d) is 5 wt.% silver nitrate, Figure 4 (e) is 6 wt.% silver nitrate.

[0074] Example 9

[0075] A method for preparing a metal reflective layer Ag / PET is provided in this embodiment using a 0.01M stannous chloride dihydrate sensitizing solution, comprising the following steps:

[0076] First, a 2.5×5 cm PET substrate was washed in an ultrasonic bath with water, acetone, and isopropanol for 15 minutes, respectively. Subsequently, it was dried in an oven at 60°C. Two 100 ml beakers, A and B, were prepared: 3.5 g of silver nitrate was weighed into beaker A and 7 g of glucose was weighed into beaker B. 70 mL of deionized water was added to each beaker A and B, respectively, and ultrasonically dispersed. 0.01 M stannous chloride dihydrate was weighed into beaker C, and 10 mL of concentrated hydrochloric acid was slowly added. Stirring was performed until the stannous chloride dihydrate was completely dissolved. Then, 40 mL of deionized water was slowly added to beaker C, stirring continuously, to prepare a 0.01 M stannous chloride sensitizing solution. The prepared PPy / PET substrate was sensitized in the sensitizing solution for 2 minutes, removed, rinsed with copious amounts of deionized water, and dried. 28 wt.% ammonia water was added dropwise to beaker A, stirring constantly, until the silver nitrate solution first turned brown and turbid and then gradually clarified, forming a silver-ammine complex solution. Mix the solutions in beakers A and B, place the sensitized PET substrate in the mixed solution, and heat in a water bath at 70°C for 10 minutes. After the reaction is complete, remove the PET, rinse with deionized water, and dry to obtain a metallic reflective layer, Ag / PET.

[0077] Example 10

[0078] This embodiment provides methods for preparing the Ag / PET metal reflective layer using 0M, 0.02M, and 0.03M stannous chloride sensitizing solutions, respectively. The rest is the same as in Example 9.

[0079] We tested the contact angles before and after sensitization, and found that the sensitizer had a significant effect on the hydrophilicity of the substrate. When the sensitizer concentration was 0.01M, the contact angle between the solution and the substrate was the best. Figure 5 (a) is 0M stannous chloride dihydrate sensitizing solution, Figure 5 (b) is 0.01M stannous chloride dihydrate sensitizing solution, Figure 5 (c) is 0.02M stannous chloride dihydrate sensitizing solution, Figure 5 (d) is 0.03M stannous chloride dihydrate sensitizing solution.

[0080] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for preparing a metal reflective layer, characterized in that: The steps include: S1. Substrate pretreatment: Wash the substrate with water, acetone, and isopropanol in an ultrasonic water bath, and then dry. S2. Preparation of a deposition precursor solution: adding 2 wt.% to 10 wt.% of silver nitrate to deionized water to form a silver nitrate solution, and ultrasonically dispersing the solution until the silver nitrate is completely dissolved to obtain a deposition precursor solution; S3. Preparation of silver ammonia complex solution: adding 20 wt.% to 28 wt.% ammonia water dropwise to the deposition precursor solution with stirring until the silver nitrate solution first turns brown and turbid and then gradually becomes clear, thereby forming a silver ammonia complex solution; S4. Preparation of a sedimentation reduction solution: adding 5 wt.% to 10 wt.% of glucose to deionized water, and ultrasonically dispersing until the glucose is completely dissolved to obtain a sedimentation reduction solution; S5. Preparation of sensitizing solution: add 0.01-0.1 mol of stannous chloride to hydrochloric acid, then add deionized water, and ultrasonically disperse until the stannous chloride is completely dissolved to obtain a sensitizing solution; S6. Substrate sensitization: The pretreated substrate is subjected to secondary treatment, then immersed in the sensitizing solution for 1-3 minutes, washed, and dried; S7. Preparation of a metal reflective layer: Mix the deposition reduction solution described in step S4 with the silver ammonia complex solution described in step S3 to form a mixed solution, immerse the sensitized substrate in the mixed solution, react in a water bath at 40-90° C. for 5-10 minutes, remove the substrate, wash it, and dry it to form a metal reflective layer.

2. The method for preparing a metal reflective layer according to claim 1, wherein: In step S1, the washing time is 13-18 minutes; the drying time is 60-80°C.

3. The method for preparing a metal reflective layer according to claim 1, wherein: In step S1 , the substrate is a transparent carrier of any shape, including a flat or curved structure; the material of the substrate includes glass, polyethylene terephthalate or acrylic board.

4. The method for preparing a metal reflective layer according to claim 1, wherein: In step S5 , the solvent is a mixed solution of hydrochloric acid and deionized water, and the volume ratio of hydrochloric acid to deionized water is 1:

4.

5. The method for preparing a metal reflective layer according to claim 1, wherein: In step S6, the secondary treatment is: adhering a high temperature resistant tape to one side of the substrate pre-treated in step S1.

6. The method for preparing a metal reflective layer according to claim 5, wherein: The high temperature resistant adhesive tape is a polyimide adhesive tape.

7. The method for preparing a metal reflective layer according to claim 1, wherein: In step S6, the drying temperature is 60-80°C.

8. The method for preparing a metal reflective layer according to claim 1, wherein: In step S7, the mass ratio of silver nitrate to glucose solute in the mixed solution is 0.5-2:1-8.

9. The method for preparing a metal reflective layer according to claim 1, wherein: In step S7, the drying temperature is 60-80°C.

10. Use of the metal reflective layer prepared by the method for preparing a metal reflective layer according to any one of claims 1 to 9 in an electrochromic device.

Images