A high-stability hydrogel electrolyte for electrochromic devices

Abstract

The present application relates to a kind of based on gelatin / polyacrylic acid-acrylamide hydrogel electrolyte electrochromic device.The electrochromic device is sandwich structure, the sandwich structure is in order from top to bottom transparent conductive electrode 1, electrochromic layer 1, electrolyte layer, electrochromic layer 2, transparent conductive electrode 2.And provide a kind of based on gelatin / polyacrylic acid-acrylamide hydrogel electrolyte electrochromic device preparation method, including a kind of high transmittance, high stability gelatin / polyacrylic acid-acrylamide hydrogel electrolyte preparation, and it is assembled as electrolyte layer electrochromic device.The present application relates to the preparation method of novel hydrogel electrolyte, simple, raw material is cheap and easy to obtain, the device can be realized under applied electric field, realize the substantial change of color and transmittance, high stability, in the field such as intelligent window, energy-saving glass has wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the preparation and application of a novel hydrogel electrolyte, in particular to the preparation of an electrochromic device based on a gelatin / polyacrylic acid-acrylamide high-stability hydrogel, and belongs to the technical field of electrochromic technology. BACKGROUND

[0002] Electrochromism refers to the phenomenon that the optical properties (transmittance, absorptivity, etc.) of a material change stably and reversibly under the action of an applied electric field, which is manifested in the reversible changes in color and transmittance. Electrochromism has potential applications in display and light radiation and transmittance management.

[0003] A typical electrochromic device is composed of five layers: transparent conductive electrode-electrochromic layer-electrolyte layer-ion storage layer-transparent conductive electrode. At present, the electrolyte layer is mainly divided into liquid electrolyte, solid electrolyte and gel electrolyte. The liquid electrolyte has complete dissociation, small system viscosity, small ion movement resistance and very high mobility, but the device has poor packaging effect and low stability; the solid electrolyte is easy to be processed into a film and has high stability after packaging, but has low ion conductivity and poor device interface combination; the gel electrolyte has the advantages of liquid electrolyte and solid electrolyte, has high ion conductivity, high stability and high mechanical strength, and is widely used in electrochromic devices.

[0004] A hydrogel is a kind of three-dimensional network structure gel with extremely high hydrophilicity. The highly cross-linked polymer network makes the hydrogel have excellent mechanical properties and deformation capacity, in addition, the hydrogel also has good light transmittance and high ion conductivity, and it has a wide application in electrochromic devices. At present, the electrochromic device has the disadvantages of low transmittance and poor stability, therefore, it is particularly important to develop a high-stability electrolyte to promote the practical application of the electrochromic device. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application provides a preparation method of a high-stability hydrogel electrolyte for an electrochromic device.

[0006] The present application provides a simple electrochromic device manufacturing method, which uses 3M double-sided tape to fix a hollow groove between two electrodes, adds a hydrogel solution, and irradiates it under the condition of an ultraviolet lamp (360 nm) to solidify it inside the device; not only can the electrolyte layer be very thin, but also the service life of the device can be increased.

[0007] A high-stability hydrogel electrolyte for an electrochromic device and a device preparation method include the following steps:

[0008] (1) Preparation of hydrogel electrolyte: under room temperature, a certain amount of acrylic acid and acrylamide is added into a DMSO / H2O=4:1 solution, after being fully stirred, an additive is added, and the solution is stirred and dissolved at 40 DEG C, and then a photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone (HMPP), a crosslinking agent N, N-methylene bisacrylamide (MMBA) and a potassium chloride salt solution are added in sequence, and a hydrogel solution is obtained after stirring;

[0009] (2) Preparation of electrode material: Prussian blue and tungsten trioxide are deposited on conductive glass by using constant current deposition and constant voltage electrodeposition, and are used as an anode and a cathode of an electrochromic device respectively;

[0010] (3) Preparation of electrochromic device: a hollow groove is fixed between the two electrodes prepared in step (2) by using 3M double-sided adhesive, the hydrogel solution prepared in step (1) is added dropwise into the groove, and the hydrogel is solidified under the irradiation of a UV lamp, so that a high-stability electrochromic device based on gelatin / polyacrylic acid-acrylamide is obtained.

[0011] The concentration of potassium chloride in step (1) is 1 mol / L.

[0012] The mass ratio of acrylic acid to acrylamide in step (1) is 1:1-5.

[0013] The crosslinking agent in step (1) is N, N-methylene bisacrylamide (MBAA), and the amount of the crosslinking agent accounts for 2% of the mass of acrylamide.

[0014] The photoinitiator in step (1) is 2-hydroxy-2-methyl-1-phenyl-1-propanone (HMPP), and the amount of the photoinitiator is 20 muL.

[0015] The additive in step (1) is gelatin; the gelatin is used as an interpenetrating network segment, and the mass of the gelatin is 0-1 g.

[0016] In the electrodeposition process of step (2), ITO conductive glass is used as a working electrode, a platinum wire is used as a counter electrode, and a silver wire is used as a reference electrode.

[0017] The present application has the following advantages:

[0018] The method for preparing the hydrogel electrolyte in the present application is simple, and the hydrogel has high transmittance; the device based on the hydrogel has excellent electrochromic performance at room temperature, and has good application prospects in the fields of intelligent color-changing windows and flexible electronic devices. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural diagram of an electrochromic device.

[0020] Figure 2The ion conductivity of the hydrogel electrolyte of Example 1, 2 and 3 at room temperature; it can be seen from the figure that the hydrogel has good ion conductivity when the gelatin content is 0.25 g.

[0021] Figure 3 The UV absorption spectrum of the electrochromic device made of the hydrogel of Example 2 at room temperature; it can be seen from the figure that the maximum absorption wavelength is at 690 nm; the electrochromic device has a wide voltage window of 1.8-1.2 V.

[0022] Figure 4 The cycle stability of the electrochromic device at room temperature; the results show that the difference in transmittance of the electrochromic device can still maintain 97.2% of the initial state after 15000 cycles at the maximum absorption wavelength of 690 nm. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application is further illustrated below in combination with examples.

[0024] Example 1

[0025] (1) Preparation of hydrogel electrolyte:

[0026] 0.333 g of acrylic acid and 1.667 g of acrylamide were added to a solution of 10 mL DMSO / H2O=4:1 and stirred until dissolved; 0.036 g of N, N-methylene bisacrylamide was added to the solution and continued to stir for 0.5 h; after dissolving 1 mol / L KCl, finally 20 μL of 2-hydroxy-2-methyl-1-phenyl-1-propanone was added, and the hydrogel solution was obtained after stirring for 30 min;

[0027] (2) Preparation of electrode:

[0028] Prussian blue film was prepared by constant current deposition method, 0.0658 g of K3Fe(CN)6, 0.0324 g of FeCl3, 0.1491 g of KCl and 1.7 mL of 36% HCl were dissolved in 20 mL of deionized water to obtain an electrodeposition solution, and deposited at a constant current of 50 μA for 800 s; polytungsten trioxide film was prepared by constant voltage deposition method, 0.825 g of Na2WO4 was dissolved in 100 mL of deionized water, 0.6 mL of H2O2 was added under stirring, and HNO3 was used to adjust the pH to 1.5. Deposited at a constant voltage of-0.65 V for 300 s; in the above electrodeposition process, ITO conductive glass was used as the working electrode, platinum wire as the counter electrode, and silver wire as the reference electrode;

[0029] (3) Preparation of electrochromic device:

[0030] A certain size and thickness of hollow groove was fixed on the ITO conductive glass on which Prussian blue film was deposited by using 3M double-sided tape, the above obtained uniform hydrogel solution was added into the groove, and the ITO conductive glass on which tungsten trioxide film was deposited was pasted, and the hydrogel was cured under the irradiation of ultraviolet lamp for 1 min to obtain the electrochromic device based on gelatin / polyacrylic acid-acrylamide hydrogel.

[0031] Example 2

[0032] (1) Preparation of hydrogel electrolyte:

[0033] 0.333 g of acrylic acid and 1.667 g of acrylamide were added into 10 mL of DMSO / H2O=4:1 solution and stirred until dissolved; 0.5 g of gelatin was weighed and added into the solution, and stirred at 40℃ until dissolved; 0.036 g of N,N-methylene bisacrylamide was added into the solution, and stirred for 0.5 h; after adding 1 mol / L KCl solution, 20 μL of 2-hydroxy-2-methyl-1-phenyl-1-propanone was finally added, and stirred for 30 min to obtain a hydrogel solution;

[0034] (2) The preparation method of electrode and electrochromic device was the same as that in Example 1.

[0035] Example 3

[0036] (1) Preparation of hydrogel electrolyte:

[0037] 0.333 g of acrylic acid and 1.667 g of acrylamide were added into 10 mL of DMSO / H2O=4:1 solution and stirred until dissolved; 0.5 g of gelatin was weighed and added into the solution, and stirred at 40℃ until dissolved; 0.036 g of N,N-methylene bisacrylamide was added into the solution, and stirred for 0.5 h; after adding 1 mol / L KCl solution, 20 μL of 2-hydroxy-2-methyl-1-phenyl-1-propanone was finally added, and stirred for 30 min to obtain a hydrogel solution;

[0038] (2) The preparation method of electrode and electrochromic device was the same as that in Example 1.

[0039] The above only describes the preferred examples of the present application, and cannot limit the protection scope of the present application, and any modification and improvement made according to the present application should be covered in the protection scope of the present application.

Claims

1. A method for preparing a gelatin / polyacrylic acid-acrylamide high-stability hydrogel-based electrochromic device, characterized in that, The gelatin / polyacrylic acid-acrylamide high-stability hydrogel-based electrochromic device is composed of two layers of indium tin oxide electrodes on which electrochromic materials are deposited and a layer of transparent hydrogel electrolyte. The method for preparing the gelatin / polyacrylic acid-acrylamide high-stability hydrogel-based electrochromic device comprises the following steps: (1) Preparation of the hydrogel electrolyte: under room temperature conditions, a certain amount of acrylic acid and acrylamide is added to a DMSO / H2O=4:1 solution, and after being fully stirred, an additive is added, and the solution is dissolved by stirring at 40°C. A photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, a crosslinking agent N,N-methylenebisacrylamide and a potassium chloride salt solution are sequentially added, and the hydrogel solution is obtained after stirring; (2) Preparation of the electrode material: Prussian blue and tungsten trioxide are deposited on conductive glass ITO by constant current deposition and constant voltage electrodeposition, respectively, as the anode and cathode of the electrochromic device; (3) Preparation of the electrochromic device: a hollow groove is fixed between the two electrodes prepared in step (2) using 3M double-sided tape, the hydrogel solution prepared in step (1) is added dropwise, and the hydrogel is cured under UV light to obtain the gelatin / polyacrylic acid-acrylamide high-stability hydrogel-based electrochromic device; The additive in step (1) is gelatin.

2. The method for preparing a gelatin / polyacrylic acid-acrylamide-based high-stability hydrogel-based electrochromic device according to claim 1, characterized by, The concentration of potassium chloride in step (1) is 1 mol / L.

3. The method for preparing a gelatin / polyacrylic acid-acrylamide-based high-stability hydrogel-based electrochromic device according to claim 1, characterized by, The mass ratio of acrylic acid to acrylamide in step (1) is 1:1-5.

4. The method for preparing a gelatin / polyacrylic acid-acrylamide-based high-stability hydrogel-based electrochromic device according to claim 1, characterized by, The crosslinking agent N,N-methylenebisacrylamide accounts for 2% of the mass of acrylamide in step (1).

5. The method for preparing a gelatin / polyacrylic acid-acrylamide-based high-stability hydrogel-based electrochromic device according to claim 1, characterized by, The amount of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone added in step (1) is 20 μL.

6. The method for preparing a gelatin / polyacrylic acid-acrylamide high stability type hydrogel-based electrochromic device according to claim 1, characterized by, The mass of gelatin in step (1) is 0-1 g.

7. The method for preparing a gelatin / polyacrylic acid-acrylamide high stability type hydrogel-based electrochromic device according to claim 1, characterized by, In the electrodeposition process of step (2), conductive glass ITO is used as the working electrode, platinum wire as the counter electrode, and silver wire as the reference electrode.

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