CN-119087720-B - Electrochromic film and preparation method and application thereof

Abstract

The invention discloses an electrochromic film, a preparation method and application thereof, and relates to the technical field of functional materials, wherein the preparation method comprises the following steps of providing a V 2 O 5 amorphous film; the lithium salt solution is used as a lithium source, the V 2 O 5 amorphous film is converted into a V 2 O 5 amorphous film containing lithium through an electrochemical lithiation method, and the V 2 O 5 amorphous film containing lithium is annealed to obtain a zeta-V 2 O 5 film doped with lithium, namely the electrochromic film. According to the invention, the electrochromic film is prepared by combining electrochemical lithiation with a subsequent annealing method, when a voltage load is applied to the electrochromic film prepared by the electrochemical lithiation method, an infrared transmission or infrared blocking state exists, the transmittance of an infrared wave band of the electrochromic film is changed greatly while the electrochromic film is changed reversibly, the infrared modulation amplitude reaches 70%, and the problem that the infrared modulation amplitude of the layered V 2 O 5 crystal film is smaller is effectively solved.

Inventors

• WEN RUITAO
• Jiao Rongji
• SHAO PEIPEI

Assignees

• 南方科技大学

Dates

Publication Date

20260505

Application Date

20240904

Claims (6)

1. 1. The preparation method of the lithium doped zeta-V 2 O 5 film is characterized by comprising the following steps: providing a V 2 O 5 amorphous film; Converting the V 2 O 5 amorphous film into a V 2 O 5 amorphous film containing lithium by using a lithium salt solution as a lithium source through an electrochemical lithiation method; After annealing the amorphous film containing lithium V 2 O 5 , li + converts amorphous V 2 O 5 into zeta-V 2 O 5 , and Li + is inserted into a channel of zeta-V 2 O 5 to obtain a lithium doped zeta-V 2 O 5 film; The electrochemical lithiation method is a constant current charging method; the constant current charging method adopts the following technological parameters: The current density is 10-30 mu A/cm 2 , the time is 200-600 s, and the lithium salt concentration is 0.5-2 mol/L; The annealing temperature is 250-450 ℃, and the annealing time is 1-5 hours; The solvent in the lithium salt solution comprises at least one of propylene carbonate, ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl carbonate and diethyl carbonate.
2. 2. The method according to claim 1, wherein the lithium salt in the lithium salt solution comprises at least one of lithium perchlorate, lithium hexafluorophosphate, lithium bis (oxalato) borate, lithium tetrafluoroborate, lithium difluorooxalato borate, lithium bis (trifluoromethylsulfonyl) imide, lithium bis (fluorosulfonyl) imide, lithium difluorophosphate, and lithium tetrafluorooxalato phosphate.
3. 3. The method of claim 1, wherein the method of preparing V 2 O 5 amorphous film comprises the steps of: Providing a substrate; And forming a V 2 O 5 amorphous film on the substrate by a magnetron sputtering method.
4. 4. A lithium-doped zeta-V 2 O 5 film produced by the process according to any one of claims 1 to 3.
5. 5. Use of the lithium-doped zeta-V 2 O 5 film according to claim 4 in the electrochromic field.
6. 6. The use according to claim 5, wherein the lithium doped ζ -V 2 O 5 film is used as electrochromic material for the production of electrochromic devices.

Description

Electrochromic film and preparation method and application thereof Technical Field The invention relates to the technical field of functional materials, in particular to an electrochromic film and a preparation method and application thereof. Background Electrochromic technology provides an effective way for the controllable adjustment of the optical properties of materials. Under the action of an electric field, oxidation-reduction reaction inside the electrochromic material can change the valence state, components or phase structure of the electrochromic material reversibly, so that the optical properties (absorptivity, transmissivity, reflectivity and the like) of the electrochromic material can change stably and reversibly in the visible, near infrared and even microwave regions. Currently, organic electrochromic materials based on organic molecules, polymers, metal organic frameworks and the like respond quickly and are rich in color. However, in practical applications, the organic electrochromic material is inferior in thermal stability, light stability, chemical stability and radiation resistance to inorganic electrochromic materials. Therefore, the inorganic electrochromic material has the characteristics of high stability and good durability, so that the inorganic electrochromic material shows greater advantages than the organic electrochromic material in different application scenes. In the electrochromic material, the absorption edge of the layered V 2O5 crystal film in the visible light band can move reversibly, and the movement of the optical absorption edge is caused by different energy band structures of different phases generated by reversible phase change. The phase change can be controlled through gradual ion intercalation, so that the optical property of the material is controlled, and dynamic and selective adjustment of visible light and near infrared spectrum is realized. Such optical characteristics are well suited to the needs of multi-mode smart windows. However, the infrared modulation amplitude of the layered V 2O5 crystal film is small, and the maximum infrared modulation can cause irreversible phase change, thereby causing reversibility and amplitude substantial attenuation of modulation, and greatly limiting the application thereof. Accordingly, the prior art is still in need of improvement and development. Disclosure of Invention Based on the defects of the prior art, the invention aims to provide an electrochromic film, a preparation method and application thereof, and aims to solve the problem that the infrared modulation amplitude of a layered V 2O5 crystal film is smaller. The technical scheme of the invention is as follows: In a first aspect of the present invention, there is provided a method for preparing an electrochromic film, comprising the steps of: providing a V 2O5 amorphous film; Converting the V 2O5 amorphous film into a V 2O5 amorphous film containing lithium by using a lithium salt solution as a lithium source through an electrochemical lithiation method; And annealing the lithium-containing V 2O5 amorphous film to obtain a lithium-doped zeta-V 2O5 film, namely the electrochromic film. Optionally, the electrochemical lithiation method is a constant current charging method. Optionally, the constant current charging method adopts the following process parameters: the current density is 10-30 mu A/cm 2, the time is 200-600 s, and the lithium salt concentration is 0.5-2 mol/L. Optionally, the lithium salt in the lithium salt solution includes at least one of lithium perchlorate, lithium hexafluorophosphate, lithium bis (oxalato) borate, lithium tetrafluoroborate, lithium difluoro (oxalato) borate, lithium bis (trifluoromethylsulfonyl) imide, lithium bis (fluorosulfonyl) imide, lithium difluoro-phosphate, and lithium tetrafluorooxalato phosphate. Optionally, the solvent in the lithium salt solution includes at least one of propylene carbonate, ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate, methylpropyl carbonate, ethyl carbonate, and diethyl carbonate. Optionally, the annealing temperature is 250-450 ℃, and the annealing time is 1-5 h. Optionally, the preparation method of the V 2O5 amorphous film comprises the following steps: Providing a substrate; And forming a V 2O5 amorphous film on the substrate by a magnetron sputtering method. In a second aspect of the invention, there is provided an electrochromic film prepared by the method of the invention as described above. In a third aspect of the invention there is provided the use of an electrochromic film as described above in the electrochromic field. Optionally, the electrochromic film is used as an electrochromic material for preparing electrochromic devices. The method has the beneficial effects that the electrochromic film is prepared by combining electrochemical lithiation with a subsequent annealing method, when a voltage load is applied to the electrochromic film prepared by the electrochemic