Broad-spectrum decoupled regulated electrochromic device, preparation method and regulation method

Abstract

The application discloses a kind of wide-spectrum decoupling regulation and control electrochromic device, preparation method and regulation and control method.The electrochromic device includes counter electrode, diaphragm, infrared and visible electrochromic layer;Diaphragm is porous membrane, and is loaded with electrolyte, electrolyte connects counter electrode and visible electrochromic layer;Infrared electrochromic layer has conductivity, and has multi-channel structure, so that electrolyte can be contacted with visible electrochromic layer through it;Visible electrochromic layer and infrared electrochromic layer form optical interference, and the thickness is below infrared light wavelength.The electrochromic device provided by the application will be able to realize visible regulation and control and infrared emission regulation and control of mutual decoupling;In addition, electrochromic layer is no longer shielded by electrolyte, counter electrode and other structure layers, can be directly observed, and overall presents the characteristics of ultrathin flexibility, more convenient and different devices are combined;At the same time, the corresponding preparation process is simple, and it is beneficial to large-area, mass production and preparation.

Description

Technical Field

[0001] This invention relates to the field of electrochromic device technology, and in particular to a broadband decoupled electrochromic device, its preparation method, and its control method. Background Technology

[0002] The widespread application of infrared heating technology has led to great attention being paid to high-emissivity infrared radiation materials. In practical applications, the light and heat environment of the Earth's surface will change significantly with day and night and seasons, requiring corresponding light / heat control technologies to adapt to them and achieve active switching between states such as heat collection and cooling. This is precisely the cutting-edge and challenging problem in related fields, and there is currently no ideal solution.

[0003] New opportunities have emerged from the dynamic spectral manipulation of visible and mid-infrared light, enabling operation at seemingly unrelated wavelengths, such as visible and mid-infrared, which differ by an order of magnitude, allowing for spectral decoupling. In principle, the on-demand manipulation of light and heat distribution in space requires compatibility between frequency band selection and dynamic control on the same surface; wide-spectral decoupling is key. These multispectral operations, such as thermal control, radiative cooling, and adaptive camouflage, can be used to hide and encode different wavelength information in the visible and mid-infrared regions, achieving unique display effects, anti-counterfeiting effects, and more. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a wide-spectrum decoupled electrochromic device, its preparation method, and its control method.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0006] In a first aspect, the present invention provides a wide-spectrum decoupled controllable electrochromic device, which includes a counter electrode, a diaphragm, an infrared electrochromic layer and a visible electrochromic layer stacked in sequence.

[0007] The membrane is a porous membrane and is loaded with an electrolyte, which connects the counter electrode and the visible electrochromic layer.

[0008] The infrared electrochromic layer is made of an electro-infrared emitting material and is conductive. The infrared electrochromic layer has a multi-channel structure so that the electrolyte can contact the visible electrochromic layer through the infrared electrochromic layer.

[0009] The visible electrochromic layer is made of a visible electrochromic material and forms optical interference with the infrared electrochromic layer, and the thickness of the visible electrochromic layer is below the infrared emission wavelength of the infrared electrochromic layer.

[0010] Secondly, the present invention also provides a method for fabricating a broadband decoupled electrochromic device, comprising:

[0011] A diaphragm is provided, wherein the diaphragm is a porous membrane;

[0012] An infrared electrochromic layer is coated on the first side of the diaphragm. The infrared electrochromic layer is made of an electro-infrared emitting material and has conductivity. The infrared electrochromic layer has a multi-channel structure.

[0013] A visible electrochromic layer is deposited on the surface of the infrared electrochromic layer. The visible electrochromic layer is made of a visible electrochromic material and forms optical interference with the infrared electrochromic layer. The thickness of the visible electrochromic layer is below the infrared emission wavelength of the infrared electrochromic layer.

[0014] A counter electrode is disposed on the second surface of the diaphragm;

[0015] And, the step of loading an electrolyte in the membrane so that the electrolyte connects the counter electrode and the visible electrochromic layer through the infrared electrochromic layer.

[0016] Thirdly, the present invention also provides a broadband decoupled electrochromic modulation method, comprising:

[0017] Provide the above-mentioned electrochromic device;

[0018] By changing the electrical conditions applied to the electrochromic device, the visible light reflection characteristics and / or infrared emission characteristics of the electrochromic device can be modulated.

[0019] Furthermore, the visible light reflection characteristics and infrared emission characteristics can be independently decoupled and controlled.

[0020] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention include at least the following:

[0021] The electrochromic device provided by this invention has electrodes and an electrochromic layer disposed on both sides of a membrane, and electrochromism is achieved through electrolyte conduction. In addition, the electrochromic layer includes an infrared electrochromic layer and a visible electrochromic layer. The infrared electrochromic layer serves as a conductive current collector, allowing current to be conducted to the visible electrochromic layer. On the other hand, it serves as an electrolyte conduction channel, allowing the electrolyte to pass through this layer and act on the photochromic layer, thus changing the visible light color. Furthermore, it serves as a functional layer for electrochromic infrared emission modulation, realizing the modulation of the infrared emission spectrum under the action of current. Based on the multifunctional infrared electrochromic layer, decoupled multi-color visible light modulation and infrared emission modulation can be achieved in a single device, meeting special application requirements.

[0022] Furthermore, this invention integrates the electrochromic layer and counter electrode of the broadband decoupled independent control device on both sides of the membrane, and impregnates the membrane with sufficient electrolyte, so that the electrochromic layer and counter electrode are connected by the electrolyte stored in the membrane. This allows the infrared and visible electrochromic layers to be directly observed without being blocked by the electrolyte, counter electrode, or other structural layers. Moreover, the overall thickness of the broadband decoupled independent control device is mainly determined by the membrane, which can reach less than 100 μm and exhibit ultra-thin and flexible characteristics, making it easier to combine with different devices and meet the application needs of different fields.

[0023] Meanwhile, the fabrication process of this wide-spectrum decoupled independent control device is simple, which is conducive to large-area and mass production.

[0024] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of an electrochromic device provided in a typical embodiment of the present invention;

[0026] Figure 2a This is a photograph of the electrochromic device before it is energized and controlled, provided in a typical embodiment of the present invention.

[0027] Figure 2b This is a photograph of the electrochromic device after being energized and controlled, provided in a typical embodiment of the present invention.

[0028] Figure 3 This is a test diagram of the visible color change response time of an electrochromic device provided in a typical embodiment of the present invention;

[0029] Figure 4 This is a test image of the temperature change of an electrochromic device under different voltages using an infrared camera, provided in a typical embodiment of the present invention.

[0030] Figure 5 This is a test diagram of the infrared response time of an electrochromic device provided in a typical embodiment of the present invention;

[0031] Figure 6 This is a photograph of the continuous change of the visible color change range of the electrochromic device under different voltages, provided in a typical embodiment of the present invention.

[0032] Figure 7 This is an infrared spectrum of an electrochromic device under different voltages, provided in a typical embodiment of the present invention.

[0033] Figure 8 This is a schematic diagram of the structure of an electrochromic device provided in another typical embodiment of the present invention;

[0034] Figure 9 This is a visible light steady-state test diagram of an electrochromic device provided in another typical embodiment of the present invention;

[0035] Figure 10a This is a typical embodiment of the present invention, showing the steady-state test diagram of the infrared high emissivity of the electrochromic device under open circuit conditions.

[0036] Figure 10b This is a typical embodiment of the present invention, showing the steady-state test diagram of the infrared low emissivity of the electrochromic device under open circuit conditions.

[0037] Figure 11 This is a photograph of the continuous change in the visible color change range of the electrochromic device provided in another typical embodiment of the present invention;

[0038] Figure 12a This is an example of infrared-visible decoupling modulation spectrum change of an electrochromic device provided in a typical embodiment of the present invention;

[0039] Figure 12b This is an example of infrared-visible decoupling modulation spectrum change of an electrochromic device provided in a typical embodiment of the present invention;

[0040] Figure 12c This is an example of infrared-visible decoupling modulation spectrum change of an electrochromic device provided in a typical embodiment of the present invention;

[0041] Figure 12d This is an example of infrared-visible decoupling modulation of an electrochromic device provided in a typical embodiment of the present invention. Detailed Implementation

[0042] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0044] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component or method step from another that has the same name, and do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0045] This invention provides a broadband decoupled electrochromic device, comprising a counter electrode, a separator, an infrared electrochromic layer, and a visible electrochromic layer stacked in sequence. The separator is a porous membrane loaded with an electrolyte, which connects the counter electrode and the visible electrochromic layer. The infrared electrochromic layer is made of an electro-infrared emitting material and is conductive. The infrared electrochromic layer has a multi-channel structure, allowing the electrolyte to contact the visible electrochromic layer via the infrared electrochromic layer. The visible electrochromic layer is made of a visible electrochromic material and forms optical interference with the infrared electrochromic layer. The thickness of the visible electrochromic layer is below the infrared emission wavelength of the infrared electrochromic layer.

[0046] This invention belongs to the field of electrochromic spectral modulation, and particularly relates to devices and methods for decoupling and modulating visible light and long-wave infrared spectroscopy. The broadband electrochromic device includes: a broadband electrochromic layer, a diaphragm, and a counter electrode layer; the diaphragm is impregnated with a sufficient amount of electrolyte; the broadband electrochromic layer has a double-layer structure, the upper layer (a sublayer away from the diaphragm) is an oxide dielectric visible electrochromic layer that is transparent in long-wave infrared, and the lower layer (a sublayer adjacent to the diaphragm) is a conductive infrared electrochromic layer.

[0047] Traditional carbon materials primarily control the spectrum in the infrared band, exhibiting a predominantly black color in the visible light range, significantly limiting their applications. Current research (e.g., Chinese invention patent CN115489177A) modifies the color of carbon-based materials by coating the surface with colored paint; however, once the visible color is fixed, it cannot be dynamically adjusted. Furthermore, the coating thickness (10-20 μm) mixed with colored pigments, and the inevitable molecular vibrational absorption of the pigments in the infrared spectral region, both degrade the original infrared performance of the variable emissivity carbon-based thin film. The main difference between this invention and some traditional solutions is that it achieves a broad-spectrum electrochromic effect from visible to infrared without a metal conductive layer. 1) The material used in the infrared electrochromic layer acts as both a conductive current collector and, through thin-film interference with the visible electrochromic layer, achieves multi-color electrochromism; 2) In addition to the visible light band, the use of the infrared electrochromic layer material also enables dynamic control of the infrared spectrum, whereas the metal layer used in traditional solutions as a conductive layer cannot achieve infrared control.

[0048] Furthermore, this invention, through the synergistic effect of color-changing layers made of different materials, can not only achieve dynamic control of a wide spectrum (0.4-25μm) in the visible-far-infrared range, but also, by utilizing the different color-changing mechanisms of the two electrochromic materials in conjunction with the color-changing mechanism of the ionic electrolyte, can achieve decoupled control of the visible and infrared spectra, i.e., multiple scenarios can occur, such as: modulation in the visible band and no modulation in the infrared band; modulation in both the visible and infrared bands; no modulation in the visible band and modulation in the infrared band; and no modulation in either the visible or infrared bands.

[0049] In many existing related technologies, infrared modulation is only concentrated in the near-infrared band (0.5-2.5μm), which cannot cover a wide spectrum and cannot achieve decoupled modulation. Furthermore, it is worth noting that, in order to fully achieve decoupling without affecting infrared modulation, this invention selects a subwavelength-thickness infrared non-destructive electrochromic layer, which will not affect the infrared performance of the carbon-based material.

[0050] In a specific implementation case, the broadband electrochromic layer consists of a porous carbon material infrared electrochromic layer and an oxide medium visible electrochromic layer, in sequence. The broadband electrochromic layers form an optical interference effect to achieve a wide color gamut and multiple colors, including yellow, orange, magenta, purple, blue, cyan, and green.

[0051] When in use, whether powered on or off, the color and brightness of the visible electrochromic layer and the emissivity of the infrared electrochromic layer are not obscured by other structural layers in the electrochromic device and can be directly observed, thus achieving a very good visual effect.

[0052] In some specific examples, the broadband electrochromic layer is a structure of infrared variable emissivity material-infrared non-destructive dielectric layer, where optical interference between layers produces multi-color effects. Furthermore, by using current-induced ion deposition, the thickness of the infrared non-destructive dielectric layer material can be adjusted, thereby regulating the constructive and destructive interference of light, achieving selective absorption and reflection of light, and thus correspondingly adjusting the structural color of the layer.

[0053] In one example, the optical interference effect formed between the broadband electrochromic layers enables the broadband decoupled independent control device to exhibit brilliant optical structural colors in the unpowered state, and in the powered state, it can achieve organic integration of optical structural colors and electrochromic colors, obtaining a color variety far exceeding the sum of the electrochromic and optical structural color varieties. Under different power-on times, the long-wave infrared band exhibits significant modulation, realizing independent decoupled control of visible color change and infrared emission, and has very distinct functional characteristics.

[0054] Regarding the specific materials of each layer, in some implementations, the electro-infrared emitting material includes any one or more combinations of carbon materials, conductive polymer materials, metal oxide materials, and metal materials, and is not limited thereto.

[0055] In some embodiments, the carbon material may include any one or a combination of two or more of carbon nanotubes, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, and carbon fibers, and is not limited thereto; as a preferred embodiment, the infrared electrochromic layer is made of materials with variable emissivity such as multi-walled carbon nanotubes and graphene.

[0056] In some embodiments, the conductive polymer material may include any one or a combination of two of polyaniline materials and polythiophene materials, and is not limited thereto.

[0057] In some embodiments, the metal oxide material may include any one or a combination of two or more of tungsten trioxide, lithium titanate, and vanadium dioxide, and is not limited thereto.

[0058] In some embodiments, the electrolyte may include any one or a combination of two or more of solid electrolytes, gel electrolytes, liquid electrolytes, and photocurable electrolytes, and is not limited thereto.

[0059] Regarding the specific structure and size characteristics of each layer, in some embodiments, the thickness of the visible electrochromic layer can be greater than 0 and less than 1000 nm, and in some embodiments it is preferably 100-250 nm.

[0060] In some embodiments, the thickness of the infrared electrochromic layer can be greater than 0 and less than 100 μm, and in some embodiments it is preferably 5 to 20 μm.

[0061] In some embodiments, the diameter of the pores in the diaphragm can be 100 to 1000 nm.

[0062] In some embodiments, the thickness of the diaphragm can be greater than 0 and less than 1000 μm, and in some embodiments it is preferably greater than 0 and less than 100 μm.

[0063] In some embodiments, the total thickness of the electrochromic device is preferably less than 150 μm.

[0064] As some typical specific implementation examples of the above-described embodiments, the thickness of the visible electrochromic layer is >0 and ≤1000nm, preferably 100nm to 250nm, to ensure that the electrolyte, while passing through the infrared electrochromic layer and contacting the visible electrochromic layer via ion and electron transport, maintains high color saturation in the static state of the device. Furthermore, in some examples, the thickness of the infrared electrochromic layer is >0 and ≤100μm, preferably 5 to 20μm, to ensure that the electrolyte can pass through without overflowing the surface, resulting in a thinner and lighter overall thickness for the broadband decoupled independent control device. In some examples, the surface of the separator is relatively flat, and multiple pores are evenly distributed on its surface. In some examples, the pore size of the pores in the separator is 100nm to 1000nm, to ensure that the electrolyte can contact the infrared electrochromic layer and, while conducting electrons to the visible electrochromic layer, maintains high color saturation in the broadband decoupled independent control device. Specifically, the thickness of the porous layer is >0 and ≤1000μm, preferably >0 and ≤100μm.

[0065] Regarding the membrane material, the porous layer can be made of organic materials, inorganic materials, or composite materials thereof, such as nylon, polysulfone (PS), polyacrylonitrile (PAN), modified polysulfone (PSF), polyvinylidene fluoride (PVDF), PVC (polyvinyl chloride), PES (polyethersulfone), PP (polypropylene), cellulose, porous metal membranes, porous metal oxide membranes, porous non-metal oxide membranes, porous carbon membranes, porous carbon paper, etc., and is not limited thereto. The material and microstructure of the membrane do not have a significant impact on the decoupling color-changing ability.

[0066] In the aforementioned device, the electrolyte is in direct contact with both the electrochromic layer and the counter electrode. For example, the infrared electrochromic layer has a porous microstructure, and the visible electrochromic layer, deposited by magnetron sputtering, also has a porous structure. This allows ions to freely pass through the electrochromic layer and naturally come into contact with it. By utilizing the physical or electrochemical behavior of ions to alter the degree of optical interference, multi-color changing is achieved—a known technical principle.

[0067] In one embodiment, the electrolyte includes a solid electrolyte, a gel electrolyte, a liquid electrolyte, and a photocurable electrolyte. The electrolyte may include one or more ionic liquids, such as 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-benzyl-3-methylimidazolium BIS[(trifluoromethyl)sulfonyl]imide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, etc., and is not limited thereto. In one example, the electrolyte layer may contain lithium salt compounds, such as LiClO4, LiBF4, LiTFSI, LiAsF6, or LiPF6. Ions contained in the electrolyte can be intercalated or adsorbed into the electrochromic layer according to the applied voltage over time, thus affecting its color change, light transmittance, and infrared properties.

[0068] Based on the above technical solution, the embodiments of the present invention also provide further improved implementation methods, namely, in some implementation methods, the diaphragm has a first side and a second side arranged opposite to each other, the infrared electrochromic layer and the visible electrochromic layer are formed on the first side to form a first electrochromic composite layer; and a back infrared electrochromic layer consistent with the infrared electrochromic layer in the first electrochromic composite layer is also provided on the second side as the counter electrode.

[0069] Using the same infrared electrochromic layer for the electrodes can be considered as an ion storage layer, which can effectively prolong the regulation steady state. However, it should be noted that in this implementation, the two symmetrically arranged infrared electrochromic layers have the same structure and functional characteristics, but this does not mean that the two layers are exactly the same material and size. As long as they can perform the corresponding functions, the above-mentioned symmetry is functional symmetry, not so-called complete symmetry.

[0070] Furthermore, in some embodiments, a back visible color-changing layer consistent with the visible electrochromic layer is also provided on the surface of the back infrared color-changing layer. The back infrared color-changing layer and the back visible color-changing layer form a second electrochromic composite layer that is functionally symmetrical to the first electrochromic composite layer.

[0071] Similarly, the symmetrical membrane structure described above is functionally symmetrical, and does not mean that the membrane layers on both sides of the diaphragm are completely identical in material, structure, and size. Of course, if this preferred embodiment is not adopted, the selection of electrodes is not limited; conductive layers such as metal layers or conductive polymer layers can be selected to conduct current and achieve its basic function.

[0072] As a typical example of the above technical solution, the counter electrode is actually a functionally symmetrical second electrochromic composite layer, including a visible oxide dielectric electrochromic layer that is transmissive in long-wave infrared, and an outer conductive infrared electrochromic layer. The second electrochromic composite layer is located on the second side of the diaphragm. Similarly, by adopting this design, the outermost layers on both sides of the broadband decoupled independent control device are electrochromic layers, and very good visual effects and variable emissivity control can be obtained on both sides.

[0073] In one embodiment, the second electrochromic composite layer can also produce optical interference to display multiple colors. Furthermore, by adjusting the thickness of the second electrochromic layer material, the constructive and destructive interference of light can be adjusted, achieving selective absorption and reflection of light, thereby allowing for corresponding adjustment of the structural color.

[0074] Similarly, by forming the second electrochromic composite layer in this application, the broadband decoupled independent control device can exhibit brilliant optical structural colors in the unpowered state, and in the powered state, it can achieve organic integration of optical structural colors and electrochromic colors, obtaining a color variety far exceeding the sum of the electrochromic and optical structural color varieties. Under different power-on times, the long-wave infrared band exhibits significant modulation. The second electrochromic composite layer works in conjunction with the aforementioned first broadband electrochromic layer, enabling the broadband decoupled independent control device of this application to exhibit colorful and variable visual effects and infrared emissivity on both sides. Moreover, the visual effects on both sides can be the same or different to meet the usage requirements of different application scenarios.

[0075] Furthermore, the aforementioned configuration not only provides dual-sided control but also enables the multi-channel infrared electrochromic layer on the opposite side to serve as a corresponding ion storage layer, storing a large number of ions. This significantly improves the stability and color richness during control. In other words, the infrared electrochromic layers on both sides can function as the aforementioned conductive / ion-conducting / infrared emitting layers. Additionally, in the dual-sided design, they can also act as ion storage layers, providing at least four functionalities in the above embodiment.

[0076] In addition, to protect and maintain the film structure, the above-mentioned devices can be wrapped and encapsulated with transparent or semi-transparent encapsulation films through thermo-press encapsulation or vacuum encapsulation to provide a complete and practical device. Of course, replacing it with other encapsulation methods or even not encapsulating it will not affect the realization of the essential functional effect.

[0077] Corresponding to the above device structure, a second aspect of the present invention also provides a method for fabricating a broadband decoupled electrochromic device, which includes the following steps:

[0078] A diaphragm is provided, wherein the diaphragm is a porous membrane.

[0079] An infrared electrochromic layer is coated on the first side of the diaphragm. The infrared electrochromic layer is made of an electro-infrared emitting material and has conductivity. The infrared electrochromic layer has a multi-channel structure.

[0080] A visible electrochromic layer is deposited on the surface of the infrared electrochromic layer. The visible electrochromic layer is made of a visible electrochromic material and forms optical interference with the infrared electrochromic layer. The thickness of the visible electrochromic layer is below the infrared emission wavelength of the infrared electrochromic layer.

[0081] A counter electrode is disposed on the second side of the diaphragm.

[0082] And, the step of loading an electrolyte in the membrane so that the electrolyte connects the counter electrode and the visible electrochromic layer through the infrared electrochromic layer.

[0083] As a typical implementation example of the above implementation scheme, the above preparation method can be implemented using the following specific process:

[0084] Step 1: Provide a diaphragm having a first side and a second side facing away from each other.

[0085] Step 2: A first broadband electrochromic layer is sequentially disposed on the first surface of the diaphragm, including a visible electrochromic layer and an infrared electrochromic layer. The first broadband electrochromic layer has an infrared variable emissivity material-infrared non-destructive dielectric layer structure, and optical interference can be generated between the layers to display multiple colors.

[0086] Step 3: Set a counter electrode on the second surface of the diaphragm.

[0087] And, step 4, filling the membrane with electrolyte.

[0088] In some implementations, the method for setting the electrodes may specifically include the following process:

[0089] A back infrared color-changing layer, consistent with the infrared electrochromic layer, is disposed on the second side of the diaphragm, serving as the counter electrode.

[0090] In some embodiments, the method for setting the counter electrode may further include the following process:

[0091] A visible electrochromic layer, consistent with the visible electrochromic layer, is then deposited on the surface of the infrared-changing layer on the back side.

[0092] In some embodiments, the method of setting the electrodes and the deposition of the visible electrochromic layer include physical deposition and / or chemical deposition.

[0093] In some embodiments, the deposition method of the visible electrochromic layer includes any one or a combination of two or more of magnetron sputtering, electron beam evaporation, thermal evaporation, and ion plating.

[0094] It should be noted that, in this invention, the operation of wetting the diaphragm with electrolyte can be performed after the first broadband electrochromic layer and the counter electrode or the second broadband electrochromic layer are set, or it can be performed before or during these operations. This indicates that the specific order of the steps in this invention is not absolutely limited to the order of the words.

[0095] The electrolyte may comprise 75-85 wt% ionic liquid and 25-15 wt% ionic salt. The ionic liquid and ionic salt are as described above. In a typical embodiment, a broadband decoupled independent control device is fabricated by the following steps:

[0096] S1. A porous membrane is provided, and a first spectral electrochromic layer is attached to the membrane, wherein the visible electrochromic layer is prepared by physical vapor deposition.

[0097] S2. Immerse the diaphragm in electrolyte, and then lead out counter electrodes from the opposite sides of the formed broadband decoupled independent control device to complete the device fabrication.

[0098] The materials, dimensions, and structures of the electrochromic layer, diaphragm, electrolyte, etc., are as described above and will not be detailed here.

[0099] As a specific application of the above-mentioned device, this embodiment of the invention also provides a broadband decoupled electrochromic modulation method, which includes the following steps:

[0100] Provide an electrochromic device according to any of the above embodiments.

[0101] By changing the electrical conditions applied to the electrochromic device, the visible light reflection characteristics and / or infrared emission characteristics of the electrochromic device can be modulated.

[0102] In some implementation schemes, the specific components include:

[0103] The visible light reflectance spectrum of the visible electrochromic layer of the electrochromic device is adjusted by regulating the voltage between the counter electrode and the infrared electrochromic layer of the electrochromic device and the voltage application time.

[0104] Furthermore, the infrared emission spectrum of the infrared electrochromic layer is adjusted by regulating the duration of the current between the counter electrode and the infrared electrochromic layer.

[0105] As some typical application examples of the above technical solutions, some embodiments of the present invention also provide a method of using the broadband decoupled independent control device, including: adjusting the potential difference between the first broadband electrochromic layer and the counter electrode, so that ions in the electrolyte stored in the porous layer are inserted into or adsorbed into the electrochromic layer, causing the refractive index and electron concentration of the electrochromic material to change, thereby dynamically controlling the color and long-wave infrared emissivity of the electrochromic device.

[0106] Some embodiments of this application also provide a display device that includes the electrochromic device.

[0107] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only for illustrating the present invention and do not limit the scope of the present invention.

[0108] Example 1

[0109] This embodiment provides a broadband decoupling independent control device structure, as follows: Figure 1 As shown, the structure includes, from top to bottom, a visible electrochromic layer 11, an infrared electrochromic layer 12, a diaphragm 13, an ion storage layer 14, and a conductive layer 15.

[0110] The diaphragm 13 is made of a nylon membrane with a thickness of about 50 μm. The nylon membrane has multiple pores distributed on it, and the pore diameter of each pore is about 800 nm to 1000 nm. These pores contain appropriate electrolytes, which are in direct contact with the first infrared electrochromic layer 11 and the ion storage layer 14, respectively.

[0111] Both the ion storage layer 14 and the conductive layer 15 are ITO layers with a thickness of approximately 200 nm. The first infrared electrochromic layer 12 is a multi-walled carbon nanotube film with a thickness of approximately 10 μm, which is tightly attached to the diaphragm 13 and has a porous structure. The first visible photochromic layer is WO3 with a thickness of approximately 129 nm.

[0112] The electrolyte is selected from 75-85 wt% of 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide salt and 25-15 wt% of LITFSI, with the total content of all components being 100 wt%.

[0113] The overall thickness of this wide-spectrum decoupled independent modulation device is 100 μm, and it can independently modulate well in both the visible and mid-infrared bands.

[0114] The method for fabricating this broadband decoupled independent control device includes:

[0115] S1. The diaphragm 13 is immersed in electrolyte to allow it to absorb an appropriate amount of electrolyte.

[0116] S2. A first infrared electrochromic layer 12 is tightly attached to the first side (front) of the diaphragm 13. A first visible electrochromic layer 11 is deposited on the first infrared electrochromic layer 12 by magnetron sputtering. An ion storage layer 14 and a conductive layer 15 are sequentially deposited on the second side (back) of the diaphragm by magnetron sputtering. Electrodes are then led out from the two opposite sides of the formed broadband decoupled independent control device to complete the device fabrication.

[0117] A photograph of a broadband decoupled independent control device obtained in this embodiment is shown below. Figure 2a and Figure 2b As shown, its color is orange before power is applied. By applying positive and negative voltages (3V to -3V) between the first broadband electrochromic layer and the conductive layer, and adjusting the voltage application time, the color of the device can be reversibly switched between orange and green. The color switching speeds are approximately 10.8s and 2.7s, respectively. See [reference needed] for details. Figure 3 As shown, the infrared emissivity changes significantly under infrared camera conditions. (See reference...) Figure 4 The infrared emissivity switching time is 280ms and 404ms. Please refer to [link / reference]. Figure 5 As shown. By gradually applying voltages of 0V, -1.5V, and -3V, the device can achieve multi-color changes of orange, yellow, and green. See reference. Figure 6 As shown, stepwise variations in long-wave infrared emissivity are achieved with different voltages (see reference). Figure 7 As shown.

[0118] Example 2

[0119] This embodiment provides a large-area flexible broadband decoupled independent control device with a structure similar to that of Embodiment 1, which also includes, from top to bottom, a first visible photochromic layer, a first infrared photochromic layer, a membrane, an ion storage layer, and a conductive layer.

[0120] The porous layer is a porous PP membrane with a thickness of approximately 25 μm. The porous PP membrane has multiple uniformly distributed pores with a pore size of approximately 1000 nm. These pores are filled with an electrolyte, which directly contacts the first visible electrochromic layer, the first infrared electrochromic layer, and the ion storage layer. The ion storage layer is a NiO layer with a thickness of approximately 200 nm. The conductive layer is an ITO layer with a thickness of approximately 200 nm. The first infrared electrochromic layer is a dense carbon nanotube film with a thickness of approximately 10 μm, tightly adhered to the surface of the porous PP membrane, and also has a porous structure. The first visible electrochromic layer is a WO3 layer with a thickness of approximately 135 nm.

[0121] The electrolyte is selected from 70-80 wt% of 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and 30-20 wt% LICLO4, with the total content of all components being 100 wt%.

[0122] A method for fabricating this broadband decoupled independent control device includes:

[0123] S1. The diaphragm is immersed in electrolyte to allow it to absorb an appropriate amount of electrolyte.

[0124] S2. A first infrared electrochromic layer is tightly attached to the first side (front) of the diaphragm. A first visible electrochromic layer is deposited on the first infrared electrochromic layer by magnetron sputtering. An ion storage layer and a conductive layer are deposited sequentially on the second side (back) of the diaphragm by magnetron sputtering. Electrodes are then led out from the two opposite sides of the formed broadband decoupled independent control device to complete the device fabrication.

[0125] The broadband decoupled independent control device fabricated in this embodiment has an overall thickness of less than 50 μm. Before being powered on, its front side is orange and its back side is brown. By applying positive and negative voltages (-4V to 4V) between the first broadband electrochromic layer and the conductive layer, the front side color of the device can be reversibly switched between orange and green, and the back side color can be reversibly switched between brown and white. Furthermore, by adjusting more precise voltage values ​​of 0V, -1.5V, and -4V, multi-color changes in the front side color—from orange to yellow to green—can be achieved.

[0126] By applying positive and negative voltages (4V to -3V) between the first broad-spectrum electrochromic layer and the conductive layer, and adjusting the voltage application time, the color of the device can be reversibly switched between orange and green, and the infrared emissivity can be significantly decoupled and controlled.

[0127] Example 3

[0128] This embodiment provides a stable, large-area, flexible, wide-spectrum decoupled independent control device, the structure of which is as follows: Figure 8 As shown, the structure includes, from top to bottom, a first visible electrochromic layer 21, a first infrared electrochromic layer 22, a diaphragm 23, a second infrared electrochromic layer 24, and a second visible electrochromic layer 25. Both infrared electrochromic layers are made of dense carbon nanotube films approximately 10 μm thick, tightly adhered to the porous PP membrane, and also possess a porous structure. The dense carbon nanotube films exhibit excellent electrical conductivity and ion storage capacity. The two visible electrochromic layers can be made of WO3 layers with a thickness of approximately 100 nm-259 nm.

[0129] The electrolyte is selected from 70-80 wt% of 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and 30-20 wt% LITFSI, with the total content of all components being 100 wt%.

[0130] A method for fabricating this broadband decoupled independent control device includes:

[0131] S1. The diaphragm is immersed in electrolyte to allow it to absorb an appropriate amount of electrolyte.

[0132] S2. A first infrared electrochromic layer is tightly attached to the first side (front) of the diaphragm. A first visible electrochromic layer is deposited on the first infrared electrochromic layer by magnetron sputtering. A second infrared electrochromic layer is tightly attached to the second side (back) of the diaphragm by magnetron sputtering. A second visible electrochromic layer is deposited on the second infrared electrochromic layer by magnetron sputtering. Electrodes are then led out from the two opposite sides of the formed broadband decoupled independent control device to complete the device fabrication.

[0133] In this embodiment, the counter electrode of the broadband decoupled independent control device is consistent with the first broadband electrochromic electrode. After applying voltage and disconnecting the power supply, it exhibits good steady-state performance in the visible light region and mid-infrared band. (Refer to...) Figure 9 and Figures 10a-10b As shown. By adopting this design, the working electrode and counter electrode of the broadband decoupled independent control device are symmetrical, resulting in good modulation amplitude and steady-state performance in the visible and mid-infrared bands.

[0134] Figure 11 The image shows the initial electrochromic device in this embodiment achieving multi-color display in the visible light. Figures 12a-12d The diagram illustrates the dynamic decoupling modulation process between the visible and infrared bands. When a short-duration negative voltage is applied (0.05–0.5 s), the visible color of the device remains unchanged, while the emissivity in the infrared band is modulated, corresponding to a visible fading and a high infrared emissivity state. Figure 12a ); Continuing to apply a negative voltage for a prolonged period (3–20 seconds), the visible color of the device changes, while its emissivity remains unchanged in the infrared band, corresponding to a visible tinting and high infrared emissivity state. Figure 12b When a short-duration positive voltage is applied (0.05–0.5 s), the visible color of the device does not change, but the infrared emissivity is modulated, corresponding to a visible colored state and a low infrared emissivity state. Figure 12c When a positive voltage is applied for an extended period (3–20 seconds), the visible color of the device changes, while its emissivity remains constant in the infrared band. This corresponds to a state of visible color fading and low infrared emissivity. Figure 12d ).

[0135] Example 4

[0136] This embodiment provides a broadband decoupled independent control device similar to Embodiment 1, except that an additional 10nm metal layer, such as W, Ti, etc., is added to the inner surface of the infrared electrochromic layer and the visible photochromic layer.

[0137] The added metal layer can improve the color saturation of the device's upper surface, and a 10nm metal layer is insufficient to affect long-wave infrared modulation. This embodiment is also applicable to Embodiments 2 and 3.

[0138] This broadband decoupled electrochromic device can achieve a variety of colors, including orange, yellow, and green, and can achieve step changes in long-wave infrared emissivity with different voltages over a short period of time.

[0139] Example 5

[0140] This embodiment provides a broadband decoupled independent control device similar to Embodiment 1, except that the infrared electrochromic layer is replaced with graphene.

[0141] Graphene also has long-wave infrared modulation capabilities, and its metallic luster naturally increases the color saturation of devices without the need for additional metal layers.

[0142] This broadband decoupled electrochromic device can achieve multi-color changes of orange, yellow, and green, and achieve step changes in long-wave infrared emissivity at different voltages. This embodiment is also applicable to Embodiments 2, 3, and 4.

[0143] Example 6

[0144] The structure of the broadband decoupled independent control device provided in this embodiment is similar to that in Embodiment 1, except that the WO3 layer is replaced with a V2O5 layer of the same thickness.

[0145] The initial color of this multi-color electrochromic device is green. When a -3V voltage is applied, the device changes to blue. When a +3V voltage is applied, the device gradually changes to yellow. The long-wave infrared emissivity changes stepwise with different voltages in a short period of time.

[0146] Example 7

[0147] The structure of the broadband decoupled independent control device provided in this embodiment is similar to that in Embodiment 1, except that the WO3 layer is replaced with a MoO3 layer of the same thickness.

[0148] The initial color of this multi-color electrochromic device is yellow. When a -3V voltage is applied, the device color gradually changes to green and then blue-gray. The long-wave infrared emissivity changes stepwise with different voltages in a short period of time.

[0149] Example 8

[0150] The structure of the broadband decoupled independent control device provided in this embodiment is similar to that in Embodiment 1, except that the WO3 layer is replaced with an Nb2O5 layer of the same thickness.

[0151] The initial color of this multi-color electrochromic device is orange. When a -3V voltage is applied, the device color gradually changes to brown and dark brown. The long-wave infrared emissivity changes stepwise with different voltages in a short period of time.

[0152] Furthermore, the inventors conducted multiple experiments with reference to the various material and size / thickness options provided above. For example, replacing the material with a porous metal oxide film or a porous conductive polymer film as the infrared electrochromic layer, both achieved the technical effect of decoupling modulation. This indicates that the main factor in achieving the corresponding decoupling modulation effect lies in the device combination structure provided by the present invention, rather than in the specific material selection and specific size parameters. Each film layer only needs to achieve its corresponding function. Its material, microstructure, thickness, and even preparation method can be adaptively selected with reference to various existing technical solutions, which will not be elaborated here.

[0153] Based on the above test results, it can be clearly stated that the electrochromic device provided in this embodiment of the invention has electrodes and an electrochromic layer disposed on both sides of the diaphragm, and electrochromism is achieved through electrolyte conduction. In addition, the electrochromic layer sequentially includes an infrared electrochromic layer and a visible electrochromic layer. The infrared electrochromic layer serves as a conductive current collector, allowing current to be conducted to the visible electrochromic layer. On the other hand, it serves as an electrolyte conduction channel, allowing the electrolyte to pass through this layer and act on the photochromic layer, thus changing the visible light color. Furthermore, it serves as a functional layer for electrochromic infrared emission modulation, realizing the modulation of the infrared emission spectrum under the action of current. Based on the multifunctional infrared electrochromic layer, decoupled multi-color visible and infrared emission modulation can be achieved in a single device, meeting special application requirements.

[0154] Furthermore, in this embodiment of the invention, the electrochromic layer and the counter electrode of the broadband decoupled independent control device are integrated on both sides of the membrane, and the membrane is impregnated with sufficient electrolyte, so that the electrochromic layer and the counter electrode are connected by the electrolyte stored in the membrane. This allows the infrared and visible electrochromic layers to be directly observed without being blocked by the electrolyte, counter electrode, or other structural layers. Moreover, the overall thickness of the broadband decoupled independent control device is mainly determined by the membrane, which can reach less than 100 μm and exhibit ultra-thin and flexible characteristics, making it easier to combine with different devices and meet the application needs of different fields.

[0155] Meanwhile, the fabrication process of this wide-spectrum decoupled independent control device is simple, which is conducive to large-area and large-volume production.

[0156] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A broadband decoupled electrochromic device, characterized in that, It includes a counter electrode, a diaphragm, an infrared electrochromic layer, and a visible electrochromic layer, which are stacked sequentially. The membrane is a porous membrane and is loaded with an electrolyte, which is connected to the counter electrode and the visible electrochromic layer. The infrared electrochromic layer is made of an electro-infrared emitting material and is conductive. The infrared electrochromic layer has a multi-channel structure so that the electrolyte can contact the visible electrochromic layer through the infrared electrochromic layer. The visible electrochromic layer is made of a visible electrochromic material and forms optical interference with the infrared electrochromic layer, and the thickness of the visible electrochromic layer is below the infrared emission wavelength of the infrared electrochromic layer.

2. The electrochromic device according to claim 1, characterized in that, The electro-infrared emitting material includes any one or a combination of two or more of the following: carbon materials, conductive polymer materials, metal oxide materials, and metal materials. The carbon material includes any one or a combination of two or more of carbon nanotubes, graphene, and carbon fibers. The conductive polymer material includes any one or a combination of two of polyaniline materials and polythiophene materials; The metal oxide material includes any one or a combination of two or more of tungsten trioxide, lithium titanate, and vanadium dioxide. The electrolyte includes any one or a combination of two or more of the following: solid electrolyte, gel electrolyte, and liquid electrolyte.

3. The electrochromic device according to claim 1, characterized in that, The thickness of the visible electrochromic layer is greater than 0 and less than 1000 nm; And / or, the thickness of the infrared electrochromic layer is greater than 0 and less than 100 μm.

4. The electrochromic device according to claim 1, characterized in that, The diaphragm has pores with a diameter of 100~1000nm; And / or, the thickness of the diaphragm is greater than 0 and less than 1000 μm; The total thickness of the electrochromic device is less than 150 μm.

5. The electrochromic device according to any one of claims 1-4, characterized in that, The diaphragm has a first side and a second side arranged opposite to each other, and the infrared electrochromic layer and the visible electrochromic layer are formed on the first side to form a first electrochromic composite layer. The second side is also provided with a back infrared electrochromic layer that is consistent with the infrared electrochromic layer in the first electrochromic composite layer, serving as the counter electrode; A visible electrochromic layer, identical to the visible electrochromic layer, is also disposed on the surface of the infrared-changing layer on the back side. The infrared-changing layer on the back side and the visible electrochromic layer on the back side together form a second electrochromic composite layer that is functionally symmetrical to the first electrochromic composite layer.

6. A method for fabricating a broadband decoupled electrochromic device, characterized in that, include: A diaphragm is provided, wherein the diaphragm is a porous membrane; An infrared electrochromic layer is coated on the first side of the diaphragm. The infrared electrochromic layer is made of an electro-infrared emitting material and has conductivity. The infrared electrochromic layer has a multi-channel structure. A visible electrochromic layer is deposited on the surface of the infrared electrochromic layer. The visible electrochromic layer is made of a visible electrochromic material and forms optical interference with the infrared electrochromic layer. The thickness of the visible electrochromic layer is below the infrared emission wavelength of the infrared electrochromic layer. A counter electrode is disposed on the second surface of the diaphragm; And, the step of loading an electrolyte in the membrane so that the electrolyte connects the counter electrode and the visible electrochromic layer through the infrared electrochromic layer.

7. The preparation method according to claim 6, characterized in that, The method for setting the electrodes specifically includes: A back infrared color-changing layer, consistent with the infrared electrochromic layer, is disposed on the second side of the diaphragm, serving as the counter electrode; A visible electrochromic layer, consistent with the visible electrochromic layer, is then deposited on the surface of the infrared-changing layer on the back side.

8. The preparation method according to claim 6, characterized in that, The deposition method of the visible electrochromic layer includes physical deposition and / or chemical deposition; The deposition method of the visible electrochromic layer includes any one or a combination of two or more of magnetron sputtering, electron beam evaporation, thermal evaporation, and ion plating.

9. A broadband decoupled electrochromic modulation method, characterized in that, include: Provide an electrochromic device according to any one of claims 1-5; By changing the electrical conditions applied to the electrochromic device, the visible light reflection characteristics and / or infrared emission characteristics of the electrochromic device can be modulated.

10. The broadband decoupled electrochromic modulation method according to claim 9, characterized in that, Specifically, it includes: By adjusting the voltage and voltage application time between the counter electrode and the infrared electrochromic layer of the electrochromic device, the visible light reflectance spectrum of the visible electrochromic layer of the electrochromic device can be adjusted. Furthermore, the infrared emission spectrum of the infrared electrochromic layer is adjusted by regulating the duration of the current between the counter electrode and the infrared electrochromic layer.

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