Material for preparing electrochromic film, electrochromic film and preparation method thereof, and electrochromic device

Abstract

The present invention provides materials for preparing electrochromic films, electrochromic films and preparation methods thereof, and electrochromic devices, belonging to the technical field of optoelectronic materials. The materials for preparing electrochromic films include sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 and deionized water, with a mass ratio of 0.02:0.1:1:5 or 0.01:0.2:1:5. The present invention also provides a method for preparing an electrochromic film, which is prepared by spin coating the material for preparing the electrochromic film on the surface of FTO glass. The present invention also provides an electrochromic film, which is prepared by the above-mentioned method for preparing the electrochromic film. The present invention also provides an electrochromic device. The present invention uses sodium carboxymethyl cellulose to form a hydrogen bond cross-linked network with the abundant hydroxyl groups on γ-cyclodextrin while fixing P2W 18 , which can prevent P2W 18 It falls off during the cycling process, thereby improving the cycling stability and light modulation range of the electrochromic device.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic materials, and in particular relates to a material for preparing an electrochromic film, an electrochromic film and a preparation method thereof, and an electrochromic device. Background Art

[0002] With the increase of world population and the acceleration of urbanization, the total energy consumption is also increasing rapidly. Global warming and energy crisis have accelerated the development of various energy-saving systems and energy-saving products. As a cathode color-changing material, polyacids have good redox activity, high chemical stability and UV stability, and can also be used as electron storage bodies to produce color changes without changing the structure. They have been widely studied in the field of electrochromism. However, the distance between clusters is far, and weak bonds are the main factor, so the conductivity of pure polyacids is poor; secondly, polyacids can be dissolved in most polar solvents, easily fall off the substrate, and have poor cycle stability. Therefore, it is urgent to develop a polyacid-based electrochromic film material, electrochromic film and electrochromic device with high cycle stability. Summary of the invention

[0003] In order to solve the above-mentioned technical problems, the present invention provides a material for preparing an electrochromic film, an electrochromic film and a preparation method thereof, and an electrochromic device. 18 (Keggin type polyacid K6[α-P2W 18 O 62 ]·14H2O), to prevent P2W 18 It falls off during the cycle, thereby improving the cycle stability of the electrochromic device.

[0004] The technical solution adopted by the present invention is:

[0005] A material for preparing an electrochromic film, comprising sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 and deionized water, the sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 The mass ratio of sodium iodide to deionized water is 0.02:0.1:1:5 or 0.01:0.2:1:5.

[0006] A method for preparing an electrochromic film, wherein the material for preparing the electrochromic film is spin-coated on a FTO glass surface, and specifically comprises the following steps:

[0007] (1) Carboxymethyl cellulose, γ-cyclodextrin, and P2W were mixed in the above mass ratio. 18 Dissolve in deionized water;

[0008] (2) Spin coating the solution obtained in step (1) onto the FTO glass surface;

[0009] (3) After spin coating, the film was dried at 60°C for 10 min to obtain an electrochromic film on the FTO glass surface.

[0010] Furthermore, during the spin coating, the coating is firstly performed at a rotation speed of 800 r / min for 10 s, and then at a rotation speed of 1500 r / min for 15 s.

[0011] Furthermore, the thickness of the electrochromic film is 500 nm.

[0012] An electrochromic film is prepared by adopting the preparation method of the electrochromic film.

[0013] The present invention also provides an electrochromic device, comprising two pieces of FTO glass, wherein the electrochromic film is loaded on the conductive surface of one piece of the FTO glass, and the other piece of the FTO glass serves as a blank FTO glass; a flexible rubber gasket and an ion transport liquid are arranged between the two pieces of FTO glass; the FTO glass loaded with the electrochromic film serves as a working electrode, the ion transport liquid serves as an electrolyte, and the blank FTO glass serves as a counter electrode to form a "sandwich" structure; the ion transport liquid is a LiI / PC electrolyte.

[0014] Furthermore, the flexible rubber gasket is used as a spacer to control the inter-electrode distance between the working electrode and the counter electrode to be 50 μm.

[0015] Furthermore, the LiI / PC electrolyte is prepared by dissolving lithium iodide in propylene carbonate to form a solution with a concentration of 0.5M.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The materials used for preparing the electrochromic film of the present invention are sodium methylcellulose, γ-cyclodextrin, P2W 18 It is mixed with deionized water and uses sodium carboxymethyl cellulose to form a hydrogen bond cross-linking network with the abundant hydroxyl groups on γ-cyclodextrin, while fixing P2W 18 , which can prevent P2W 18 It falls off during the cycle, thereby improving the cycle stability of the electrochromic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the electrochromic device of the present invention.

[0019] Figure 2 This is a long-term cycle stability test graph of the electrochromic device prepared in Example 1 after ultraviolet visible light of 600nm and an applied voltage of 1V-(-1.2V).

[0020] Figure 3 This is a long-term cycle stability test graph of the electrochromic device prepared in Example 2 after applying a voltage of 1V to (-1.2V) under ultraviolet visible light of 600nm.

[0021] Figure 4 This is a long-term cycle stability test chart of the electrochromic device prepared in Example 1 after applying a voltage of 1V to (-1.2V) under ultraviolet visible light of 600nm.

[0022] Figure 5 This is a long-term cycle stability test chart of the electrochromic device prepared in Example 2 after applying a voltage of 1V to (-1.2V) under ultraviolet visible light of 600nm.

[0023] In the figure, 1-FTO glass, 2-electrochromic film; 3-ion transport liquid; 4-flexible rubber gasket. DETAILED DESCRIPTION

[0024] In order to highlight the technical advantages and excellent performance of the present invention, the following will be further described in conjunction with the accompanying drawings and specific embodiments. The following specific embodiments are only used for the present invention, and the specific implementation process can also be adjusted according to the understanding of technicians and actual conditions.

[0025] Example 1

[0026] An electrochromic film material, comprising sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 and deionized water, the sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 The mass ratio of sodium iodide to deionized water is 0.02:0.1:1:5.

[0027] P2W 18 Keggin type polyacid K6[α-P2W 18 O 62 ]·14H2O, the preparation method is the prior art, refer to the P2W described in the patent publication number CN114721197B 18 The preparation method is just that.

[0028] A method for preparing an electrochromic film, wherein the electrochromic film material is spin-coated on a surface of a FTO glass 1, and specifically comprises the following steps:

[0029] (1) Carboxymethyl cellulose, γ-cyclodextrin, and P2W were mixed in the above mass ratio. 18 Dissolve in deionized water;

[0030] (2) Spin coating the solution obtained in step (1) on the surface of FTO glass 1; during the spin coating, first spin coating at a speed of 800 r / min for 10 seconds, and then spin coating at a speed of 1500 r / min for 15 seconds;

[0031] (3) After spin coating, the film was dried at 60° C. for 10 min to prepare an electrochromic film 2 on the surface of the FTO glass 1. The thickness of the prepared electrochromic film 2 was 500 nm.

[0032] An electrochromic film is prepared by adopting the preparation method of the electrochromic film.

[0033] like Figure 1 As shown, an electrochromic device comprises two pieces of FTO glass 1, wherein the electrochromic film 2 is loaded on the conductive surface of one of the FTO glass 1, and the other FTO glass 1 serves as a blank FTO glass 1, and a flexible rubber gasket 4 and an ion transport liquid 3 are arranged between the two FTO glass 1; the FTO glass 1 loaded with the electrochromic film 2 serves as a working electrode, the ion transport liquid 3 serves as an electrolyte, and the blank FTO glass 1 serves as a counter electrode to form a "sandwich" structure; the ion transport liquid 3 is a LiI / PC electrolyte.

[0034] The flexible rubber gasket 4 is used as a spacer to control the inter-electrode distance between the working electrode and the counter electrode to be 50 μm.

[0035] The LiI / PC electrolyte is prepared by dissolving lithium iodide in propylene carbonate to form a solution with a concentration of 0.5M.

[0036] Performance test: The electrochromic device was subjected to long-term cycle stability test under UV visible light 600nm and applied voltage 1V-(-1.2V). Figure 2 As shown, the electrochromic device prepared in Example 1 can be stably cycled for 3200 times, and ΔT is reduced to 80% of the initial value (ΔT is the difference between the transmittance T in the faded state and the transmittance T in the colored state).

[0037] Example 2

[0038] The difference from Example 1 is that: an electrochromic film material includes sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 and deionized water, the sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 The mass ratio of sodium iodide to deionized water is 0.01:0.2:1:5.

[0039] Performance test: The electrochromic device was subjected to long-term cycle stability test under UV visible light 600nm and applied voltage 1V-(-1.2V). Figure 3As shown, the electrochromic device prepared in Example 2 can be stably cycled for 2400 times, and ΔT is reduced to 80% of the initial value.

[0040] Comparative Example 1

[0041] The difference from Example 1 is that no sodium carboxymethyl cellulose is added to the electrochromic film material, that is, sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 The mass ratio of sodium iodide and deionized water is 0:0.1:1:5.

[0042] The rest are the same as in Example 1.

[0043] Performance test: The electrochromic device was subjected to long-term cycle stability test under UV visible light 600nm and applied voltage 1V-(-1.2V). Figure 4 As shown, the electrochromic device prepared in Comparative Example 1 can be stably cycled for 1000 cycles, and ΔT is reduced to 80% of the initial value.

[0044] Comparative Example 2

[0045] The difference from Example 1 is that no γ-cyclodextrin is added to the electrochromic film material, that is, sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 The mass ratio of sodium iodide and deionized water is 0.05:0:1:5.

[0046] The rest are the same as in Example 1.

[0047] Performance test: The electrochromic device was subjected to long-term cycle stability test under UV visible light 600nm and applied voltage 1V-(-1.2V). Figure 5 As shown, the electrochromic device prepared in Comparative Example 1 can be stably cycled for 1800 cycles, and ΔT is reduced to 80% of the initial value.

[0048] It can be seen that the cyclic stability of Example 1 and Example 2 is higher than that of Comparative Example 1 and Comparative Example 2. By using sodium carboxymethyl cellulose to form a hydrogen bond cross-linking network with abundant hydroxyl groups on γ-cyclodextrin, P2W is fixed. 18 , can prevent polyacid P2W 18 It falls off during the cycle, thereby improving the cycle stability of the electrochromic device.

[0049] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present invention. As long as these changes do not deviate from the concept of the present invention, they all belong to the protection scope of the present invention.

Claims

1. A material for preparing an electrochromic film, characterized in that: Including sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 and deionized water, the P2W 18 Keggin type polyacid K6[α-P2W 18 O 62 ]·14H2O; the sodium carboxymethyl cellulose, γ-cyclodextrin, P2W 18 The mass ratio of sodium iodide to deionized water is 0.02:0.1:1:5 or 0.01:0.2:1:

5.

2. A method for preparing an electrochromic film, comprising: spin coating the material for preparing an electrochromic film as claimed in claim 1 on a FTO glass surface, wherein: The specific steps include: (1) Carboxymethyl cellulose, γ-cyclodextrin, and P2W were mixed in the above mass ratio. 18 Dissolve in deionized water; (2) Spin coating the solution obtained in step (1) onto the FTO glass surface; (3) After spin coating, the film was dried at 60°C for 10 min to obtain an electrochromic film on the FTO glass surface.

3. The method for preparing the electrochromic film according to claim 2, characterized in that: During the spin coating, the coating was firstly performed at a rotation speed of 800 r / min for 10 s, and then at a rotation speed of 1500 r / min for 15 s.

4. The method for preparing the electrochromic film according to claim 2, characterized in that: The thickness of the electrochromic film is 500 nm.

5. An electrochromic film, prepared by the method for preparing an electrochromic film as claimed in any one of claims 2 to 4.

6. An electrochromic device, characterized in that Comprising the electrochromic film as claimed in claim 5.

7. The electrochromic device according to claim 6, characterized in that: The electrochromic device comprises two pieces of FTO glass, wherein the electrochromic film as claimed in claim 5 is loaded on the conductive surface of one piece of the FTO glass, and the other piece of the FTO glass serves as a blank FTO glass, and a flexible rubber gasket and an ion transport liquid are arranged between the two pieces of FTO glass; the FTO glass loaded with the electrochromic film serves as a working electrode, the ion transport liquid serves as an electrolyte, and the blank FTO glass serves as a counter electrode to form a "sandwich" structure; the ion transport liquid is a LiI / PC electrolyte.

8. The electrochromic device according to claim 7, characterized in that: The flexible rubber gasket is used as a spacer to control the inter-electrode distance between the working electrode and the counter electrode to be 50 μm.

9. The electrochromic device according to claim 7, characterized in that: The LiI / PC electrolyte is prepared by dissolving lithium iodide in propylene carbonate to form a solution with a concentration of 0.5M.

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