Preparation method of Fe and Cu ion double-doped V2O5 electrochromic film

Abstract

The invention discloses a preparation method of a Fe and Cu ion double-doped V2O5 electrochromic film. The method comprises the following steps: firstly, putting V2O5 into a proper amount of deionized water, and carrying out ultrasonic dispersion and magnetic stirring to obtain a homogeneous V2O5 solution; then FeCl3 and CuCl2 are added to serve as a Fe source and a Cu source respectively, a proper amount of povidone is introduced to serve as an auxiliary solvent, and heating, stirring and aging are conducted, so that a doped sol system which is uniform in dispersion and good in stability is obtained; dropwise adding the prepared sol to the surface of the treated FTO conductive glass, spin-coating to form a film, and drying; and finally, performing heat treatment on the dried sample subjected to primary film formation in a tubular furnace to form a well-crystallized Fe and Cu doped V2O5 film. The Fe and Cu ion double-doped V2O5 electrochromic film obtained by the preparation method disclosed by the invention has good electrochromic performance. The preparation method provided by the invention is simple and easy to operate, has practical feasibility and is low in overall cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochromic material preparation, and particularly relates to a preparation method of Fe and Cu ion double-doped V2O5 electrochromic film. BACKGROUND

[0002] With the continuous growth of global energy demand and the increasing environmental pollution problem, energy saving and sustainable development have become important goals of social development, and scientific researchers are actively developing new materials to promote the innovative development of energy storage technology and energy saving field. Electrochromic material is a material that can undergo reversible color change under the action of an applied electric field. Its optical properties (such as reflectivity, transmittance, and absorbance) change with the change of electric field intensity, showing dynamic adjustment of color and transparency. Electrochromic materials have unique advantages in intelligent window systems, low-power display technology and dynamic optical control devices due to their color change characteristics, and have received widespread attention from researchers in the field of functional materials in recent years.

[0003] In the 1930s, the electrochromic phenomenon was first discovered, but it did not attract the attention of scientists at that time. In the 1960s, British scholar Plant first proposed the concept of electrochromism when studying organic dyes and carried out systematic research experiments, which promoted the field to enter the scientific field of view. In 1969, American scientist S.K. Deb prepared the first electrochromic device using amorphous tungsten trioxide (WO3) film, and later he proposed the "oxygen vacancy color center" mechanism, laying the theoretical foundation for inorganic electrochromic materials. From the 1980s to the 1990s, scientists focused on the mechanism and performance optimization of inorganic electrochromic materials (such as WO3, NiO, V2O5, etc.), while the research on organic electrochromic materials also began to enter the exploration stage. In 1990, electrochromic devices entered the practical stage, and American scientist C.M. Lampert proposed the concept of "smart light-adjusting window (Smart Window)", which promoted the application of electrochromic devices in the field of building energy saving. After years of research, electrochromic technology has gradually moved from the laboratory to practical application, and its development process reflects the deep integration of materials science, optics and engineering technology, and has attracted more and more attention from people.

[0004] Vanadium pentoxide (V2O5) is a transition metal oxide material with excellent electrochromic performance, widely used in smart windows, optical adjustment and display devices. V2O5 is usually light yellow or light color in the unexcited state, and can undergo significant color change to present dark color or even blue color when an electric field or current is applied. However, according to the existing research data, the unmodified vanadium oxide film still has several key technical obstacles in practical engineering application: its color range is mostly limited to the blue-gray spectrum (CIE Lab color coordinate a* value less than 2.0), and it is difficult to achieve the demand of multi-color system dynamic regulation; the corrosive components in the electrolyte can easily cause irreversible oxidation-reduction reaction of vanadium ions, resulting in more than 30% optical performance decay after 500 cycles; the low lithium ion diffusion coefficient (about 10 -12 cm 2 / s) and the high interface charge transfer impedance (>200Ω·cm 2 ) jointly restrict the response speed of the device and make it difficult to meet the real-time regulation demand. SUMMARY

[0005] In order to solve the above problems of vanadium pentoxide (V2O5) electrochromic film, the purpose of the present application is to provide a preparation method of Fe, Cu ion double-doped V2O5 electrochromic film, so as to improve the electrochromic performance of V2O5 electrochromic film.

[0006] In order to achieve the above purpose, the preparation method of Fe, Cu ion double-doped V2O5 electrochromic film provided by the present application comprises the following steps in order:

[0007] (1) Put V2O5 in a proper amount of deionized water, promote its preliminary dispersion by using ultrasonic dispersion technology, and then heat treat under the condition of magnetic stirring until V2O5 is completely dissolved to form a homogeneous solution; then add FeCl3 and CuCl2 as Fe source and Cu source respectively, and ensure their uniform dispersion in the system by continuous heating and stirring; finally introduce a proper amount of povidone as an auxiliary solvent, heat and stir for a certain time under constant stirring rate; finally make the mixed system undergo a certain aging process, and finally obtain a doped sol system which is uniformly dispersed and has good stability.

[0008] (2) Drop the prepared above sol on the surface of the treated FTO conductive glass, spin-coat into a film, and dry; then, place the preliminarily formed film sample after drying in a tube furnace for heat treatment, to form a Fe, Cu doped V2O5 film with good crystallization.

[0009] In step (1), the volume ratio of V2O5 to deionized water is 20-30:100, the amount of FeCl3 and CuCl2 is 1-5 mol / L and 2-4 mol / L respectively, the amount of povidone is 3-6 mol / L, the temperature and stirring time of heating and stirring are 50-70 DEG C and 1-2h respectively, and the final aging time is 8-12h.

[0010] In step (2), the spin coating rate is 1200-1700 rpm, the spin coating time is 12-18s, the drying temperature and time after spin coating film are 60-70 DEG C and 10-20min respectively, and the heat treatment temperature and time are 400-450 DEG C and 1-2h respectively.

[0011] The Fe, Cu ion double-doped V2O5 electrochromic film preparation method provided by the application has the following beneficial effects:

[0012] (1) The Fe, Cu ion double-doped V2O5 electrochromic film prepared by the application has good electrochromic performance after various tests.

[0013] (2) The preparation method provided by the application is simple and easy to operate, has practical feasibility, and the prepared Fe, Cu ion double-doped V2O5 electrochromic film has low cost and no pollution. DETAILED DESCRIPTION

[0014] The following examples can enable a person skilled in the art to more fully understand the application, but do not limit the application in any way.

[0015] Example 1

[0016] A Fe, Cu ion double-doped V2O5 electrochromic film preparation method comprises the following steps:

[0017] (1) V2O5 is placed in an appropriate amount of deionized water, the volume ratio is 20:100, ultrasonic dispersion technology is used to promote its preliminary dispersion, then magnetic stirring is carried out at 50 DEG C for 2h until V2O5 is completely dissolved to form a homogeneous solution; then 2 mol / L and 3 mol / L of FeCl3 and CuCl2 are added as Fe source and Cu source respectively, and magnetic stirring is carried out at 50 DEG C for 2h; finally, 3 mol / L of povidone is introduced as an auxiliary solvent, magnetic stirring is carried out at 50 DEG C for 2h, and finally the mixed system is aged for 8h to obtain a doped sol system which is uniformly dispersed and has good stability.

[0018] (2) The prepared sol is added dropwise to the surface of the treated FTO conductive glass, and is spin-coated into a film, the spin-coating rate and the spin-coating time being 1200 rpm and 18 s respectively, the film is dried at 60℃ for 20 min after spin-coating, and finally the dried film is placed in a tube furnace for heat treatment, the heat treatment temperature and time being 400℃ and 2 h respectively, and a well-crystallized Fe, Cu-doped V2O5 film is obtained.

[0019] Example 2

[0020] A preparation method of an Fe, Cu ion double-doped V2O5 electrochromic film, comprising the following steps:

[0021] (1) V2O5 is placed in a proper amount of deionized water, the volume ratio being 30:100, and an ultrasonic dispersion technique is used to promote its preliminary dispersion, then it is magnetically stirred at 60℃ for 1 h until V2O5 is completely dissolved to form a homogeneous solution, then 3 mol / L and 4 mol / L FeCl3 and CuCl2 are added respectively as Fe and Cu sources, and the mixture is magnetically stirred at 60℃ for 1 h, finally 5 mol / L povidone is introduced as an auxiliary solvent, the mixture is magnetically stirred at 60℃ for 1 h, and finally the mixed system is aged for 8 h, and a doped sol system with uniform dispersion and good stability is obtained.

[0022] (2) The prepared sol is added dropwise to the surface of the treated FTO conductive glass, and is spin-coated into a film, the spin-coating rate and the spin-coating time being 1500 rpm and 15 s respectively, the film is dried at 70℃ for 10 min after spin-coating, and finally the dried film is placed in a tube furnace for heat treatment, the heat treatment temperature and time being 450℃ and 1 h respectively, and a well-crystallized Fe, Cu-doped V2O5 film is obtained.

[0023] The application is described in detail through the examples, but the content described is only exemplary embodiments of the application, and cannot be considered as limiting the implementation scope of the application. The protection scope of the application is defined by the claims. Any similar technical solution that utilizes the technical solutions described in the application, or is inspired by the technical solutions of the application, and achieves the above technical effects within the spirit and protection scope of the application, or any equivalent changes and improvements to the application scope, shall still belong to the patent protection scope of the application. It should be noted that, in order to clearly describe the application, the description of the application omits the description of some components and processes that are not directly and obviously related to the protection scope of the application but are known to those skilled in the art.

Claims

1. A method for preparing a Fe and Cu ion-doped V₂O₅ electrochromic thin film, characterized in that: The preparation method includes the following steps performed in sequence: First, V2O5 is placed in an appropriate amount of deionized water, ultrasonically dispersed and magnetically stirred to obtain a homogeneous V2O5 solution; then, FeCl3 and CuCl2 are added as Fe and Cu sources, respectively, and an appropriate amount of polyvinyl ketone is introduced as an auxiliary solvent, heated and stirred, and aged to obtain a uniformly dispersed and stable doped sol system; the prepared sol is dropped onto the surface of the treated FTO conductive glass, spin-coated to form a film, and dried; finally, the dried sample with preliminary film formation is placed in a tube furnace for heat treatment to form a well-crystallized Fe and Cu doped V2O5 thin film.

2. The Fe and Cu ion-doped V₂O₅ electrochromic thin film according to claim 1, characterized in that: In step (1), the volume ratio of V2O5 to deionized water is 20-30:100, the amounts of FeCl3 and CuCl2 are 1-5 mol / L and 2-4 mol / L respectively, the amount of povidone is 3-6 mol / L, the heating and stirring temperature and stirring time are 50-70℃ and 1-2 h respectively, and the final aging time is 8-12 h.

3. The Fe and Cu ion-doped V₂O₅ electrochromic thin film according to claim 1, characterized in that: In step (2), the spin coating rate is 1200-1700 rpm, the spin coating time is 12-18 s, the drying temperature and drying time after spin coating are 60-70℃ and 10-20 min respectively, and the heat treatment temperature and time are 400-450℃ and 1-2 h respectively.