An orthorhombic phase of Nb 18 V4O 55 Electrochromic film and its preparation method and application

Abstract

The present invention relates to the field of electrochromic technology, in particular to an orthorhombic phase Nb 18 V4O 55 Electrochromic film and its preparation method and application. 18 V4O 55 The electrochromic film not only has excellent electrochromic ability, but can also achieve a "warm state" mode of electrochromic dual-band regulation using the intrinsic properties of the material. It also has a large optical modulation amplitude. The electrochromic film also has the characteristics of fast kinetic response and high cyclic stability. These characteristics make it have the potential for commercial applications in smart windows, display devices and other fields.

Description

Technical Field

[0001] The present invention relates to the field of electrochromic technology, in particular to an orthorhombic phase Nb 18 V4O 55 Electrochromic film, preparation method and application thereof. Background Art

[0002] Electrochromism refers to the phenomenon in which, under the influence of an external electric field, cations and electrons present in an electrolyte are reversibly injected or extracted from the material, causing a redox reaction within the material, thereby reversibly changing the material's optical properties. Currently, the earliest and most widespread application of electrochromism is in smart windows. The electrochromic layer of smart windows has adjustable optical transmittance under the influence of an electric field, which can achieve the regulation of indoor lighting and thermal radiation, reducing the energy consumption required for heating, cooling, and lighting in buildings. It also improves natural light indoors and is expected to alleviate the worsening problem of urban light pollution.

[0003] At present, most electrochromic materials are concentrated in the visible light band for regulation, while the energy of sunlight is mainly concentrated in the visible light and near-infrared bands, of which visible light and near-infrared each account for nearly 50%. Therefore, the development of electrochromic materials that can independently control the transmittance of visible light and near-infrared is of great significance for the widespread application of electrochromic materials.

[0004] The use of dual-band electrochromic materials in smart windows is expected to achieve four adjustable modes: "bright," "dark," "warm," and "cold." The "bright" state refers to the film being transparent, meaning it maintains high transmittance for both visible and near-infrared light. The "dark" state has low or no transmittance for both visible and near-infrared light. The "warm" state maintains high transmittance for the near-infrared band and low transmittance for the visible light band. The "cold" state maintains high transmittance for the visible light band and low transmittance for the near-infrared band.

[0005] Despite extensive research in this field, dual-band electrochromic materials currently only achieve sequential switching between "bright," "cold," and "dark" modes, with few reports demonstrating a "warm" mode. In current reports, achieving a "warm" mode is typically achieved by using composite cathode and anode electrochromic materials or by combining the properties of counter electrodes into devices. Alternatively, achieving a "warm" mode can be achieved by adjusting the electrolyte or integrating electrochromism with other technologies. Notably, achieving a "warm" mode using only single-component dual-band electrochromic materials is difficult. Furthermore, in current reports demonstrating a "warm" mode, complex preparation and high costs have limited their widespread application in smart windows. Furthermore, not only "warm" materials and devices, but all dual-band electrochromic materials and devices still face challenges such as poor performance, poor interfacial contact, and poor cycling stability. Overall, while researchers have made significant progress in the field of dual-band electrochromism by optimizing material composition and device structure, many key issues remain to be addressed to promote future research and widespread application, particularly the development of "warm" materials and devices.

[0006] Therefore, more new electrochromic materials are yet to be discovered, and existing technologies are yet to be improved and developed. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an orthorhombic phase Nb 18 V4O 55 The electrochromic film and its preparation method and application are intended to solve the problems that existing single-component dual-band electrochromic materials are difficult to achieve the "warm state" mode, and the current methods for achieving the "warm state" mode are complex and the preparation cost is high.

[0008] The technical solutions of the present invention are as follows:

[0009] The first aspect of the present invention provides an orthorhombic phase Nb 18 V4O 55 Application of materials in electrochromic films.

[0010] The second aspect of the present invention provides an orthorhombic phase Nb 18 V4O 55 A method for preparing an electrochromic film, comprising the steps of:

[0011] The magnetron sputtering method is used to co-sputter metal Nb and metal V on the substrate surface to obtain amorphous Nb on the substrate surface. 18 V4O 55 film;

[0012] For the amorphous Nb 18 V4O 55The film was annealed to obtain orthorhombic Nb 18 V4O 55 Electrochromic film.

[0013] Optionally, in the magnetron sputtering method, a metal niobium target and a metal vanadium target are used to co-sputter metal Nb and metal V on the substrate surface, wherein the power supply power of the metal niobium target is 100W to 200W, and the power supply power of the metal vanadium target is 25W to 125W.

[0014] Optionally, the metal niobium target and the metal vanadium target co-sputter metal Nb and metal V on the substrate surface in a molar ratio of 1:0.2 to 0.45.

[0015] Optionally, the distance between the center position of the surface of the metal niobium target and the center position of the surface of the metal vanadium target and the center position of the substrate surface is 120 mm to 150 mm.

[0016] Optionally, the working gases of the magnetron sputtering method are oxygen and argon, wherein the ratio of oxygen to argon is 5 sccm:45 sccm, and the gas pressure is 1 Pa to 1.5 Pa.

[0017] Optionally, in the annealing treatment, the annealing temperature is 550° C. to 650° C., and the annealing time is 120 min to 300 min.

[0018] The third aspect of the present invention provides an orthorhombic phase Nb 18 V4O 55 Electrochromic film, wherein the orthorhombic phase Nb 18 V4O 55 The electrochromic film is prepared by a preparation method.

[0019] Optionally, the orthorhombic phase Nb 18 V4O 55 The thickness of the electrochromic film is 300nm to 350nm.

[0020] The fourth aspect of the present invention provides an electrochromic device, which comprises a transparent conductive layer, an electrochromic layer, an electrolyte layer and an ion storage layer, wherein the electrochromic layer comprises the orthorhombic phase Nb 18 V4O 55 Electrochromic film.

[0021] Beneficial effect: The present invention discloses orthorhombic phase Nb 18 V4O 55 The application of materials in electrochromic films, and the orthorhombic phase Nb was successfully prepared by magnetron sputtering combined with annealing method. 18 V4O 55The electrochromic film is simple and low-cost, and the prepared orthorhombic phase Nb 18 V4O 55 The electrochromic film not only has excellent electrochromic ability, but can also achieve a "warm state" mode of electrochromic dual-band regulation using the intrinsic properties of the material. It also has a large optical modulation amplitude. The electrochromic film also has the characteristics of fast kinetic response and high cyclic stability. These characteristics make it have the potential for commercial applications in smart windows, display devices and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The orthorhombic Nb prepared in Example 1-6 18 V4O 55 Comparison of the XRD diffraction pattern of the electrochromic film and the PDF standard card.

[0023] Figure 2 Orthorhombic Nb 18 V4O 55 A graph showing the full-band optical transmittance changes of the electrochromic film at different voltages during the electrochromic process.

[0024] Figure 3 Orthorhombic Nb 18 V4O 55 A graph showing the change in single-wavelength optical transmittance of an electrochromic film over time during the electrochromic process.

[0025] Figure 4 Orthorhombic Nb at different scanning rates 18 V4O 55 Single-wavelength optical transmittance variation of electrochromic films.

[0026] Figure 5 Orthorhombic Nb 18 V4O 55 Single-wavelength optical transmittance variation of electrochromic film during cyclic stability test. DETAILED DESCRIPTION

[0027] The present invention provides an electrochromic film, a preparation method thereof, and applications thereof. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0028] The embodiment of the present invention provides an orthorhombic phase Nb 18 V4O 55 Application of materials in electrochromic films.

[0029] The embodiment of the present invention discloses orthorhombic phase Nb 18V4O 55 Application of materials in electrochromic films, existing technology on orthorhombic phase Nb 18 V4O 55 The research of materials is concentrated in the fields of electrocatalysis and batteries, and there has been no report on electrochromism. 18 V4O 55 The material is used in electrochromic thin films to obtain orthorhombic Nb 18 V4O 55 The electrochromic film not only has excellent electrochromic ability and strong optical modulation ability, for example, the modulation ability in the visible light band (550nm) is about 70%, and the modulation ability in the near-infrared band (1100nm) is about 85%; it can also achieve a "warm state" mode of electrochromic dual-band regulation, that is, the transmittance of the visible light band can be reduced first while the transmittance of the near-infrared band remains unchanged, and as the voltage continues to decrease, it is expanded to a decrease in the entire visible light and near-infrared. And it achieves this "warm state" regulation mode by utilizing the intrinsic properties of the material on the inorganic oxide electrochromic material, without relying on the design of the material microstructure, composition or device. In addition, the orthorhombic phase Nb 18 V4O 55 Electrochromic films also have the characteristics of fast kinetic response and high cycle stability, which make orthorhombic Nb 18 V4O 55 The film has potential for commercial applications in smart windows, display devices and other fields.

[0030] The embodiment of the present invention also provides an orthorhombic phase Nb 18 V4O 55 A method for preparing an electrochromic film, comprising the steps of:

[0031] S1. Use magnetron sputtering method to co-sputter metal Nb and metal V on the substrate surface to obtain amorphous Nb on the substrate surface. 18 V4O 55 film;

[0032] S2, the amorphous Nb 18 V4O 55 The film was annealed to obtain orthorhombic Nb 18 V4O 55 Electrochromic film.

[0033] The present invention innovatively uses a magnetron sputtering method combined with an annealing method to successfully prepare the orthorhombic phase Nb 18 V4O 55Compared with the traditional chemical synthesis method, the electrochromic film prepared by the method of the present invention is simple to operate, and the electrochromic film not only has excellent electrochromic performance and strong optical modulation ability, but also has an electrochromic "warm state" adjustment mode.

[0034] The orthorhombic Nb in the embodiment of the present invention 18 V4O 55 The electrochromic film is prepared by magnetron sputtering deposition combined with post-annealing, wherein the magnetron sputtering and annealing steps can be completed separately, or can be obtained by magnetron sputtering combined with in-situ heating annealing.

[0035] In some embodiments, in the magnetron sputtering method, a metal niobium target and a metal vanadium target are used to co-sputter metal Nb and metal V on the surface of the substrate, wherein the power of the metal niobium target is 100W-200W (for example, 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W, 200W), the power of the metal vanadium target is 25W-125W (for example, 25W, 35W, 45W, 55W, 65W, 75W, 85W, 95W, 105W, 115W, 125W), and the distance between the center position of the surface of the metal niobium target and the center position of the substrate surface is 120mm-150mm (for example, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm).

[0036] In this embodiment, the power of the metal niobium target and the metal vanadium target is set within the above range, and amorphous Nb can be obtained by sputtering metal niobium and metal vanadium in a suitable mixing ratio on the substrate surface. 18 V4O 55 The film can be annealed to obtain orthorhombic Nb 18 V4O 55 Electrochromic thin film. Setting the relative positions of the metal niobium target and the metal vanadium target to the substrate within the above range is conducive to making the composition of the thin film obtained by magnetron sputtering uniform.

[0037] In some embodiments, the magnetron sputtering method uses a metal niobium target and a metal vanadium target to co-sputter metal Nb and metal V on the substrate surface in a molar ratio of 1:0.2 to 0.45, for example, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4 or 1:0.45. Within this molar ratio range, the amorphous Nb 18 V4O 55 The films can form the same orthorhombic crystal structure after annealing, and finally the orthorhombic phase Nb 18 V4O 555Electrochromic film can achieve excellent electrochromic ability.

[0038] In some embodiments, the orthorhombic Nb 18 V4O 555 The electrochromic film may also include doping elements, wherein the doping elements are selected from one or more of tungsten, titanium, nickel, and molybdenum. Since the doping ratio of the doping elements is very small, the Nb 18 V4O 55 The original crystal structure of the material, the electrochromic film can still have good electrochromic ability. For example, the orthorhombic phase Nb 18 V4O 555 The electrochromic film may include tungsten doping elements, in which case the chemical formula of the material contained in the electrochromic film will become Nb 18 W x V4O 55 (where x is 0 to 2), but the material will still retain the original Nb 18 V4O 55 The crystal structure of the material's orthorhombic phase.

[0039] In some embodiments, the working gases of the magnetron sputtering method are oxygen and argon, wherein the ratio of oxygen to argon is 5 sccm:45 sccm, and the gas pressure is 1 Pa to 1.5 Pa. If necessary, the oxygen flow rate can be appropriately increased according to the situation. The relatively high oxygen flow rate will not cause the amorphous Nb to form. 18 V4O 55 The material is in an oxygen-deficient state, so the oxygen flow needs to be regulated. Furthermore, adjusting the air pressure usually affects the density of the material. When adjusted within an appropriate range, lower air pressure makes the material denser, and generally has better electrochromic properties.

[0040] In some embodiments, during the annealing process, the annealing temperature is 550° C. to 650° C. (e.g., 550° C., 560° C., 570° C., 580° C., 590° C., 600° C., 610° C., 620° C., 630° C., 640° C., 650° C.), and the annealing time is 120 min to 300 min (e.g., 120 min., 150 min., 200 min., 250 min., 300 min.) Annealing the material under these parameters prevents the material from crystallizing into other crystalline phases due to excessively high temperatures, and the appropriate annealing time allows the material to achieve optimal crystallinity.

[0041] The embodiment of the present invention also provides an orthorhombic phase Nb 18 V4O 55 The electrochromic film, wherein the orthorhombic Nb 18 V4O 55The electrochromic film is prepared by a preparation method.

[0042] The orthorhombic phase Nb provided by the present invention 18 V4O 55 The electrochromic film not only has excellent electrochromic ability and strong optical modulation ability, but also can realize the "warm state" mode of electrochromic dual-band regulation. In addition, it has the characteristics of fast kinetic response and high cycle stability. These characteristics make the orthorhombic phase Nb 18 V4O 55 Electrochromic films have potential for commercial applications in smart windows, display devices and other fields.

[0043] In some embodiments, the orthorhombic Nb 18 V4O 55 The thickness of the electrochromic film is 300 nm to 350 nm. Within this thickness range, the film has both large optical modulation capability and high response speed.

[0044] The present invention also provides an electrochromic device, which comprises a transparent conductive layer, an electrochromic layer, an electrolyte layer and an ion storage layer, wherein the electrochromic layer comprises the orthorhombic phase Nb 18 V4O 55 Electrochromic film.

[0045] The present invention will be further described below with reference to specific examples.

[0046] Example 1

[0047] This embodiment provides an orthorhombic phase Nb 18 V4O 55 The electrochromic film and its preparation method are as follows:

[0048] Amorphous Nb was deposited by co-sputtering metal Nb and metal V on ITO quartz glass using magnetron sputtering. 18 V4O 55 Thin film, when depositing the thin film, oxygen and argon are introduced into the magnetron sputtering chamber, the ratio of oxygen and argon is 5sccm:45sccm, and the gas pressure is about 1.2Pa. Metal niobium target and metal vanadium target are used as target materials, and a DC sputtering power supply is used. The power of the metal niobium target is 150W, and the power of the metal vanadium target is 76W. The metal niobium target and the metal vanadium target co-sputter the metal Nb and metal V on the ITO quartz glass surface in a molar ratio of 1:0.25. During the deposition process, the sample stage is rotated to maintain the element ratio and thickness of the thin film uniform, and the surface center position of the metal niobium target and the metal vanadium target is kept at a distance of 150mm from the center position of the substrate surface. Amorphous Nb deposited by magnetron sputtering method 18V4O 55 The film appears as a light yellow transparent film.

[0049] The amorphous Nb deposited by magnetron sputtering 18 V4O 55 The film was placed in a muffle furnace for high temperature annealing treatment. The temperature was first raised from room temperature to 600 ° C in 60 minutes, then kept at 600 ° C for 120 minutes, and finally cooled naturally to room temperature. The annealing process was carried out in an atmospheric environment to obtain orthorhombic phase Nb 18 V4O 55 Electrochromic film.

[0050] Example 2

[0051] The preparation method of Example 2 is the same as that of Example 1, except that the power of the metal vanadium target is adjusted to 67W, wherein the metal niobium target and the metal vanadium target are co-sputtered on the surface of the ITO quartz glass with a molar ratio of metal Nb and metal V of 1:0.2. Finally, orthorhombic Nb 18 V4O 55 Electrochromic film.

[0052] Example 3

[0053] The preparation method of Example 3 is the same as that of Example 1, except that the power of the metal vanadium target is adjusted to 85W, wherein the metal niobium target and the metal vanadium target are co-sputtered on the surface of the ITO quartz glass with a molar ratio of metal Nb and metal V of 1:0.3. Finally, orthorhombic Nb 18 V4O 55 Electrochromic film.

[0054] Example 4

[0055] The preparation method of Example 4 is the same as that of Example 1, except that the power of the metal vanadium target is adjusted to 92W, and the metal niobium target and the metal vanadium target are co-sputtered on the surface of the ITO quartz glass with a molar ratio of metal Nb and metal V of 1:0.35. Finally, orthorhombic Nb 18 V4O 55 Electrochromic film.

[0056] Example 5

[0057] The preparation method of Example 5 is the same as that of Example 1, except that the power of the metal vanadium target is adjusted to 100W, wherein the metal niobium target and the metal vanadium target are co-sputtered on the surface of the ITO quartz glass with a molar ratio of metal Nb and metal V of 1:0.4. Finally, orthorhombic Nb 18 V4O 55 Electrochromic film.

[0058] Example 6

[0059] The preparation method of Example 6 is the same as that of Example 1, except that the power of the metal vanadium target is adjusted to 106W, wherein the metal niobium target and the metal vanadium target are co-sputtered on the surface of the ITO quartz glass with a molar ratio of metal Nb and metal V of 1:0.45. Finally, orthorhombic Nb 18 V4O 55 Electrochromic film.

[0060] The orthorhombic Nb prepared in Examples 1-6 was characterized by X-ray diffraction (XRD). 18 V4O 55 The crystal structure of the electrochromic film is characterized. Comparing the obtained XRD pattern with the PDF standard card can determine the crystal structure of the prepared electrochromic film. XRD is a structural testing method mainly used for phase analysis and determination of material crystallinity. Its principle is that when a beam of X-rays is incident on a crystal, because the crystal is composed of a large number of microscopic material units (atoms, ions, molecules, etc.) arranged in an orderly manner according to certain rules, the X-rays scattered by different crystal planes interfere with each other, resulting in strong X-ray diffraction in certain special directions. According to the Bragg equation "2dsinθ=nλ", the angle and intensity of the diffraction line are closely related to the crystal structure. By analyzing the angle and intensity of the diffraction line, the lattice information of the material can be obtained.

[0061] Figure 1 The orthorhombic Nb prepared in Example 1-6 18 V4O 55 The XRD diffraction patterns of the electrochromic films are compared with the PDF standard card. According to the figure, the electrochromic films prepared in Examples 1-6 all have orthorhombic Nb 18 V4O 55 crystal structure.

[0062] Example 7

[0063] This example explores the orthorhombic phase Nb prepared in Example 1. 18 V4O 55 The optical modulation amplitude and dual-band regulation "warm state" adjustment mode of the electrochromic film are as follows:

[0064] The orthorhombic phase Nb prepared in Example 1 18 V4O 55The electrochromic film was electrochemically tested in a glove box (water and oxygen content were less than 0.01) using a three-electrode system, where the electrolyte was a 1 mol / L lithium perchlorate (LiClO4) solution of propylene carbonate (PC), the counter electrode and reference electrode were lithium foil, and the working electrode was the orthorhombic Nb prepared in Example 1. 18 V4O 55 The electrochromic film was electrochemically cycled using cyclic voltammetry (CV) with a voltage window of 1.25 V to 4 V and a scan rate of 1 mV / s. At the same time, the full-band optical transmittance changes of the film during the electrochromic process were recorded in situ.

[0065] The in-situ optical transmittance is recorded by a spectrometer with a spectral range of 400nm-1600nm. The specific method is to place the sample in a 5×5×5cm cubic quartz electrolytic cell, which is placed between a tungsten-halogen lamp and a detector. The transmittance of the tungsten-halogen lamp through the electrolytic cell filled with electrolyte is set to 100%, and the transmittance is set to 0% when the light source is completely blocked. During the test, both the full spectrum (400nm-1600nm) and the single-wavelength spectrum (550nm, 1100nm) are measured in situ.

[0066] Figure 2 Orthorhombic Nb 18 V4O 55 The full-band optical transmittance change diagram of the electrochromic film at different voltages during the electrochromic process. According to the figure, the visible light transmittance of the film decreases slightly from the initial state to the coloring potential of 2.4V; there is a significant regulation of the visible light band in the process from 2.4V to 2.0V; when it is lower than 2.0V, the film shows a sharp drop in full-band transmittance; the "warm state" mode appears at a coloring potential of 2.0V, at which time the visible light (550nm) transmittance and the near-infrared (1100nm) transmittance have a difference of more than 25%.

[0067] Figure 3 Orthorhombic Nb 18 V4O 55 The graph of the single wavelength optical transmittance of the electrochromic film during the electrochromic process shows that there is an obvious order of modulation of visible light and near infrared, and the transmittance of visible light and near infrared shows the largest difference when the coloring potential is 2.0V. In general, the orthorhombic phase Nb 18 V4O 55 The electrochromic process of electrochromic film is divided into two stages. First, the transmittance of the visible light band decreases alone and presents a "warm state". Then the transmittance of the entire band decreases together until it is completely colored and presents a "dark state". 18 V4O 55The electrochromic film achieved a large optical modulation amplitude of more than 70% for visible light and more than 85% for near-infrared light in this process. This shows that the orthorhombic phase Nb 18 V4O 55 The electrochromic film only uses a single-component single-layer electrochromic material to achieve the "warm state" mode with the intrinsic properties of the material, and at the same time has a large optical modulation amplitude, providing a new option for dual-band electrochromism.

[0068] Example 8

[0069] This example explores the orthorhombic phase Nb prepared in Example 1. 18 V4O 55 The fast kinetic response characteristics of electrochromic films. The kinetics or response speed of electrochromic materials is an important parameter for evaluating their commercial application potential and is also one of the goals pursued by researchers in this field. In-situ spectra of thin films recorded at different CV cycle scan rates are important for discussing the dynamics of lithium ion injection and extraction. The modulation amplitude of the film at different scan rates clearly reflects the kinetic characteristics of the electrochromic film. The details are as follows:

[0070] The three-electrode system in Example 7 was used to measure the orthorhombic Nb 18 V4O 55 The electrochromic film was subjected to electrochemical cycling test with a voltage window of 1.25V to 4V. The film was cycled for 3 times at scanning speeds of 100mV / s, 50mV / s, 20mV / s, 10mV / s, 5mV / s and 1mV / s respectively. The single-wavelength optical transmittance of the film at 550nm and 1100nm was recorded at the same time, representing the visible light band and the near-infrared band, respectively.

[0071] Figure 4 is the orthorhombic Nb at different scanning rates 18 V4O 55 The single-wavelength optical transmittance variation diagram of the electrochromic film shows that the optical modulation amplitude in the visible light band at a scanning rate of 1mV / s is 71.6%, and the optical modulation amplitude in the near-infrared band is 86.6%; at a higher scanning rate of 20mV / s, the optical modulation amplitude in the visible light band drops to 65.3%, and the optical modulation amplitude in the near-infrared band drops to 80.5%, but still maintains more than 90% of full coloration. Visible orthorhombic Nb 18 V4O 55 The electrochromic film can still maintain a sufficiently low colored state transmittance at a higher scanning rate of 20 mV / s, and the cycle time is only a quarter of that of 1 mV / s, which shows that the electrochromic film of the present invention has high coloring efficiency and fast response speed.

[0072] Example 9

[0073] This example explores the orthorhombic phase Nb prepared in Example 1. 18 V4O 55 The high cycle stability of electrochromic films is also one of the important indicators for evaluating the performance of electrochromic films. The long-term stable operation of the film is the prerequisite for its transition from basic research to industrial production applications. The details are as follows:

[0074] The three-electrode system in Example 7 was used to conduct constant voltage to the orthorhombic Nb prepared in Example 1. 18 V4O 55 The electrochromic film was subjected to electrochemical cycling test. This method can complete the injection and extraction of lithium ions in the film in the shortest time and significantly shorten the time required for the experiment. Specifically, the constant voltage electrochemical cycle adopts a three-stage method. First, it is maintained at a voltage of 1.8V for 20s, showing a "warm state" mode; then it is maintained at a voltage of 1.2V for 30s to make the film completely colored; finally, it is maintained at a high voltage of 3.5V for 30s to make the film completely faded and present a "bright state". A total of orthorhombic Nb 18 V4O 55 The electrochromic film was subjected to 20,500 constant voltage electrochemical cycles, and the single-wavelength optical transmittance of the film was recorded at 550 nm and 1100 nm, representing the visible light band and near-infrared band, respectively.

[0075] Figure 5 It is orthorhombic Nb 18 V4O 55 The single-wavelength optical transmittance change graph of the electrochromic film undergoing a cyclic stability test shows that after a 20,500-cycle test, the film can still maintain an optical transmittance equivalent to that of the initial state, but the optical modulation amplitude of the film decreases slightly, from 68% to 60% in the visible light band, and from 85% to 73% in the near-infrared band. The performance attenuation is less than 15%, which shows that the electrochromic film of the present invention has good cyclic stability and is expected to be applied commercially on a large scale.

[0076] In summary, the orthorhombic phase Nb 18 V4O 55 The electrochromic film achieves a "warm state" mode through the intrinsic properties of the material, and has a large optical modulation amplitude, fast dynamic response characteristics and high cycle stability. These characteristics make it have the potential for commercial applications in smart windows, display devices and other fields.

[0077] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. An orthorhombic phase Nb 18 V4O 55 Application of the material in an electrochromic film; the electrochromic film is a dual-band electrochromic film that is sequentially regulated by visible light and near-infrared light; The electrochromic film can achieve a "warm" mode of electrochromic dual-band regulation, that is, the transmittance of the visible light band is first reduced while the transmittance of the near-infrared band remains unchanged. As the voltage continues to decrease, the decrease is expanded to the entire visible light and near-infrared band. The method for preparing the electrochromic film comprises the steps of: The magnetron sputtering method is used to co-sputter metal Nb and metal V on the substrate surface to obtain amorphous Nb on the substrate surface. 18 V4O 55 film; For the amorphous Nb 18 V4O 55 The film is annealed to obtain an electrochromic film; The molar ratio of the metal Nb to the metal V is 1:0.2-0.

45.

2. A method for preparing an electrochromic film according to claim 1, characterized in that: Including steps: The magnetron sputtering method is used to co-sputter metal Nb and metal V on the substrate surface to obtain amorphous Nb on the substrate surface. 18 V4O 55 film; For the amorphous Nb 18 V4O 55 The film is annealed to obtain an electrochromic film.

3. The method for preparing the electrochromic film according to claim 2, wherein: In the magnetron sputtering method, a metal niobium target and a metal vanadium target are used to co-sputter metal Nb and metal V on the substrate surface, wherein the power supply power of the metal niobium target is 100W-200W, and the power supply power of the metal vanadium target is 25W-125W.

4. The method for preparing the electrochromic film according to claim 3, wherein: The metal niobium target and the metal vanadium target co-sputter metal Nb and metal V on the substrate surface in a molar ratio of 1:0.2 to 0.

45.

5. The method for preparing the electrochromic film according to claim 3, wherein: The distance between the center position of the surface of the metal niobium target and the center position of the metal vanadium target and the center position of the substrate surface is 120 mm to 150 mm.

6. The method for preparing the electrochromic film according to claim 2, wherein: The working gases of the magnetron sputtering method are oxygen and argon, wherein the ratio of oxygen to argon is 5 sccm:45 sccm, and the gas pressure is 1 Pa to 1.5 Pa.

7. The method for preparing the electrochromic film according to claim 2, wherein: In the annealing treatment, the annealing temperature is 550° C. to 650° C., and the annealing time is 120 min to 300 min.

8. An electrochromic film, characterized in that: The product is prepared by the preparation method according to any one of claims 2 to 7.

9. The electrochromic film according to claim 8, characterized in that: The thickness of the electrochromic film is 300nm to 350nm.

10. An electrochromic device, characterized in that: The invention comprises a transparent conductive layer, an electrochromic layer, an electrolyte layer and an ion storage layer, wherein the electrochromic layer comprises the electrochromic film according to claim 8.

Images