Flexible electrochromic device for heat management of curved transparent enclosure structure

Abstract

The invention belongs to the technical field of electrochromic devices, and relates to a flexible electrochromic device for heat management of a curved transparent enclosure structure. The electrode is formed by assembling flexible polyethylene glycol terephthalate-indium tin oxide as transparent conductive electrodes on the two sides to clamp a silver-based gel electrolyte. The device is simple in preparation method, controllable in composition and structure and easy to expand; the deposition quality of silver ions is improved through electrode surface plasma cleaning and modification; by applying and removing voltage, the device has reversible dual working modes: an initial state is a solar heating mode, and at the moment, the device has high sunlight transmissivity; voltage is applied to the device to excite deposition of silver on the outer side electrode, at the moment, a radiation cooling mode is adopted, and at the moment, the device has high sunlight reflectivity and high and medium far infrared emissivity; the device has excellent sunlight modulation capability and mechanical stability, and has great application prospects in the aspect of all-season dynamic thermal management of curved transparent enclosure structures such as buildings and automobiles.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochromic devices, and specifically relates to a flexible electrochromic device for thermal management of a curved transparent enclosure structure, thermal management of a transparent enclosure structure, and particularly to all-season thermal management of a curved transparent enclosure structure. Background Art

[0002] Transparent envelopes, including building windows, skylights, curtain walls, atriums, and car sunroofs, are among the least energy-efficient components, accounting for about 60% of total energy losses. This stems from the "static" optical properties of traditional glass, which cannot adapt to time and weather changes. To address this issue, dynamically adjustable transparent envelopes that can regulate solar energy entry have become a promising solution to reduce energy consumption in buildings and cars.

[0003] Electrochromic devices can actively regulate the amount of solar energy that passes through transparent envelopes, providing a significant opportunity to improve energy efficiency. Conventional electrochromic dynamic glazing regulates solar transmittance primarily by changing the absorption of solar radiation. In the opaque state, only a small fraction of sunlight is reflected. On hot days, such dynamic glazing may re-emit 20% to 40% of the absorbed solar heat into the interior, increasing the cooling load. In hot weather conditions, reflecting incident sunlight is more beneficial for energy conservation and thermal comfort. Building on electrochromic control of sunlight, the cooling load can be further reduced by enhancing the radiative cooling effect through high emissivity in the mid-infrared range.

[0004] At present, although some devices integrating electrochromic and radiative cooling have been applied to horizontal surfaces with thermal management requirements such as vertical windows and skylights, the thermal management of curved transparent enclosure surfaces that are widely present in buildings and cars still requires further development and design. Summary of the invention

[0005] In order to solve the problem of lack of dynamic thermal management means for curved transparent enclosure structures in the prior art, the present invention discloses a flexible electrochromic device based on reversible silver electrochemical deposition. The device includes a flexible transparent conductive electrode, a silver-based gel electrolyte and a transparent packaging material. The device structure is composed of two offset and parallel transparent flexible conductive electrodes sandwiching a silver-based gel electrolyte to form a three-layer electrode-electrolyte-electrode structure, and the entire device is sealed by a transparent packaging material. Through this device, dynamic thermal management of curved transparent enclosure structures in all seasons can be achieved, the transmitted and reflected solar energy can be effectively adjusted, and the energy efficiency of buildings can be improved.

[0006] To achieve the above object, the technical solution of the present invention is as follows: The present invention provides a flexible electrochromic device for thermal management of a curved transparent enclosure structure; the device comprises a flexible transparent conductive electrode, a silver-based gel electrolyte and a transparent packaging material, wherein the flexible transparent conductive electrode is a polyethylene terephthalate-indium tin oxide (PET-ITO) electrode, two flexible transparent conductive electrodes are placed in parallel and staggered positions, and are bonded and fixed by a transparent packaging material, and the silver-based gel electrolyte is injected between the two flexible transparent conductive electrodes to form a three-layer structure of electrode-electrolyte-electrode.

[0007] Furthermore, in order to improve the deposition quality of silver ions, the surface of the flexible transparent conductive electrode needs to be cleaned and surface modified, and the cleaning and surface modification treatment includes the following steps: ultrasonic cleaning using acetone, isopropanol, ethanol and deionized water in sequence, followed by oxygen plasma cleaning, and surface modification using 3-mercaptopropyltrimethoxysilane: the trimethoxysilane group can be anchored on the hydroxyl group on the surface of the ITO electrode, and the terminal thiol can strongly interact with the deposited Ag metal to ensure the stability and high reflectivity of the silver film.

[0008] The surface modification using 3-mercaptopropyltrimethoxysilane includes the following steps: immersing the flexible transparent conductive electrode in a mixed solution of toluene / 3-mercaptopropyltrimethoxysilane (the volume ratio of 3-mercaptopropyltrimethoxysilane to toluene is 1:40) for 12 hours. Subsequently, ultrasonic treatment is performed in ethanol for 10-15 minutes to remove the residual unbound monomers on the electrode surface. Finally, the surface-modified electrode is dried at 60°C in a nitrogen atmosphere for 2-3 hours.

[0009] Furthermore, the silver-based gel electrolyte is prepared by dissolving silver nitrate, cupric chloride, tetrabutylammonium bromide and polyvinyl butyral in dimethyl sulfoxide, wherein the molar ratio of bromine, silver and copper is 25:5:1, and the ratio of the mass of dimethyl sulfoxide to the sum of the mass of silver nitrate, cupric chloride and tetrabutylammonium bromide is 15:1; then 10% of the total mass of the system polyvinyl butyral is added, and the mixture is stirred and mixed at 25°C-60°C for 12 hours to gel the electrolyte.

[0010] Furthermore, the electrode arrangement and packaging: two flexible transparent conductive electrodes are placed in parallel and staggered, with the indium tin oxide (ITO) conductive layer on the inner side of the electrode and the polyethylene terephthalate (PET) substrate layer on the outer side. Both sides of the staggered electrodes are exposed 0.5cm-1cm for applying voltage. A transparent packaging material with a thickness of 0.5mm is used to bond the two staggered transparent flexible conductive electrodes, and a 0.1mm wide injection gap is left during the bonding process to facilitate the injection of silver-based gel electrolyte.

[0011] The transparent packaging material is VHB closed-cell acrylic foam.

[0012] Furthermore, silver-based gel electrolyte injection: silver-based gel electrolyte is injected between two parallel, offset and bonded transparent flexible conductive electrodes until the electrode gap is filled to form a three-layer structure of electrode-electrolyte-electrode.

[0013] Furthermore, after the silver-based gel electrolyte is injected through the injection gap, the injection gap is encapsulated using UV curing glue to form a complete flexible electrochromic device, thereby ensuring the long-term stability and sealing of the device.

[0014] The present invention also provides an application of a flexible electrochromic device for thermal management of a curved transparent enclosure structure. The flexible electrochromic device can be pasted on the surface of a curved transparent enclosure structure. By applying or removing a voltage of -2.5V, the device can be controlled to reversibly switch between radiation cooling and solar heating modes, thereby dynamically adjusting the thermal management performance of the curved structure to adapt to different environmental conditions.

[0015] Through the above scheme, the present invention can achieve dynamic optical and thermal management of curved transparent enclosure structures, provide efficient, all-season energy control means for buildings and cars, and improve the energy-saving performance of buildings and cars and indoor thermal comfort.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a flexible electrochromic device for thermal management of curved transparent enclosure structures. The device achieves all-season thermal management of curved transparent enclosure structures by dynamically adjusting the transmission and reflection of solar energy, which can effectively improve the energy efficiency of buildings and cars. Whether it is heating demand in winter or cooling demand in summer, the best thermal management effect can be achieved by adjusting the electrochromic state.

[0017] Through plasma cleaning and modification of the electrode surface, the binding force of silver ions on the electrode surface is significantly improved, and the solar reflectivity of the device in the radiation cooling state is enhanced. The device controls the reversible electrodeposition of silver ions by applying and removing a voltage of -2.5V, so that the device can dynamically switch between the radiation cooling mode and the solar heating mode. In the radiation cooling mode, the application of voltage promotes the deposition of silver on the electrode, so that the device exhibits high reflectivity in the visible and near-infrared light ranges, blocking solar heat from entering the interior of the building, thereby reducing indoor temperature and air conditioning energy consumption. In the solar heating mode, by removing the voltage, the silver ions are dissolved from the electrode surface, the device returns to its initial state, and the transmittance of sunlight is increased, so that solar energy can enter the interior of the building through the transparent enclosure structure, raising the indoor temperature and reducing heating energy consumption.

[0018] In the present invention, the outer layer of the device is polyethylene terephthalate (PET), which has high emissivity in the mid- and far-infrared bands, and can achieve the effect of radiation cooling in combination with the high reflectivity of the device when a voltage of -2.5V is applied to sunlight. The high emission in the mid- and far-infrared bands enables the device to dissipate excess heat through spontaneous thermal radiation, further improving the cooling effect. Under direct sunlight, the surface temperature of the enclosure structure can even be reduced to below the ambient temperature, thereby achieving a state close to "net zero energy consumption" and achieving a more efficient energy-saving effect.

[0019] The electrochromic device has a simple preparation process, a reasonable and controllable structural design, and is easy to expand to large-scale production. The device has excellent sunlight modulation capability and mechanical stability, and its flexibility and adaptability make it very suitable for use in complex curved transparent enclosures, especially in the all-season dynamic thermal management of curved transparent enclosures such as modern buildings and automobiles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram showing the device structure and actual working status; Among them, a is the preparation process of the flexible electrochromic device, b is a schematic diagram of the three-layer symmetrical structure of the flexible electrochromic device, c is a photo of the two modes of radiation cooling and solar heating of the actual device, and d is the repeated reversible changes of the flexible electrochromic device in the straight and bent states. DETAILED DESCRIPTION

[0021] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Example 1

[0022] The flexible electrochromic device is prepared as follows: a) Using commercial polyethylene terephthalate-indium tin oxide electrodes (purchased from South China Xiangcheng Technology Co., Ltd., resistance 40 ohms, polyethylene terephthalate thickness 0.125 mm, indium tin oxide film thickness 55 nm), the electrode surface was cleaned and surface modified. The cleaning steps were ultrasonically cleaned with acetone, isopropanol, ethanol and deionized water for 15 minutes, and then dried at 60 ° C in a nitrogen atmosphere for 3 hours. Subsequently, oxygen plasma cleaning was performed for 15 minutes, and 3-mercaptopropyltrimethoxysilane was used for surface modification: the flexible transparent conductive electrode was immersed in a mixed solution of toluene / 3-mercaptopropyltrimethoxysilane (the volume ratio of 3-mercaptopropyltrimethoxysilane to toluene was 1:40) for 12 hours. Subsequently, ultrasonic treatment was performed in ethanol for 15 minutes to remove the residual unbound monomers on the electrode surface. Finally, the surface-modified electrode was dried at 60 ° C in a nitrogen atmosphere for 3 hours.

[0023] b) 0.17 g of silver nitrate, 0.026 g of copper chloride, and 1.612 g of tetrabutylammonium bromide were dissolved in 25 ml of dimethyl sulfoxide (DMSO), and 10% of polyvinyl butyral was added to the mixture, and the mixture was stirred at 800 rpm for 12 h at 25 °C to prepare a silver-based gel electrolyte.

[0024] c) Two flexible transparent conductive electrodes are placed in a parallel staggered manner, with the indium tin oxide conductive layer on the inner side of the electrode and the polyethylene terephthalate (PET) substrate layer on the outer side. Both sides of the staggered electrodes are exposed 0.5 cm, and 3M VHB double-sided transparent adhesive with a thickness of 0.5 mm is used to bond the two electrodes, and a 0.1 mm wide injection gap is left during the bonding process.

[0025] d) A silver-based gel electrolyte is injected between two symmetrically offset and bonded transparent flexible conductive electrodes until the electrode gap is filled to form a three-layer structure of electrode-electrolyte-electrode.

[0026] e) The electrolyte injection port is encapsulated using UV curing glue (brand: MECHANIC) to obtain a flexible electrochromic device, wherein the polyethylene terephthalate-indium tin oxide layer has a thickness of 0.125 mm and the silver-based gel electrolyte has a thickness of 0.5 mm.

[0027] The optical properties of the device in the wavelength range of 0.3-2.5μm were characterized using an ultraviolet-visible near-infrared spectrometer (brand: Shimadzu, model: UV-3600i Plus). The test results show that the sunlight transmittance of the flexible electrochromic device in the initial solar heating state is 72.95%, and the sunlight reflectance is 15.71%; after applying a pulse voltage of -2.5V using a waveform generator (brand: Agilent, model 33210A), a dense silver nanofilm (bright, high sunlight reflectance) is deposited on the negative electrode. At this time, the device is in a radiation cooling state, and the sunlight reflectance of the device is 89.11%, and the sunlight transmittance is 0.02%.

[0028] The emissivity of the device in the wavelength range of 8-13 μm was tested using a Fourier transform infrared spectrometer (brand: Thermo Fisher Scientific, model Nicolet iS50). The average infrared emissivity of the outer layer of the flexible electrochromic device was 91.75%. Example 2

[0029] The flexible electrochromic device is prepared as follows: a) Using commercial polyethylene terephthalate-indium tin oxide electrodes (purchased from South China Xiangcheng Technology Co., Ltd., resistance 40 ohms, polyethylene terephthalate thickness 0.125 mm, indium tin oxide film thickness 55 nm), the electrode surface was cleaned and surface modified. The cleaning steps were ultrasonically cleaned with acetone, isopropanol, ethanol and deionized water for 10 minutes, and then dried at 60 ° C in a nitrogen atmosphere for 2 hours. Subsequently, oxygen plasma cleaning was performed for 10 minutes, and 3-mercaptopropyltrimethoxysilane was used for surface modification: the flexible transparent conductive electrode was immersed in a mixed solution of toluene / 3-mercaptopropyltrimethoxysilane (the volume ratio of 3-mercaptopropyltrimethoxysilane to toluene was 1:40) for 12 hours. Subsequently, ultrasonic treatment was performed in ethanol for 10 minutes to remove the residual unbound monomers on the electrode surface. Finally, the surface-modified electrode was dried at 60 ° C in a nitrogen atmosphere for 2 hours.

[0030] b) 0.17 g of silver nitrate, 0.026 g of copper chloride, and 1.612 g of tetrabutylammonium bromide were dissolved in 25 ml of dimethyl sulfoxide (DMSO), and 10% of polyvinyl butyral was added to the mixture, and the mixture was stirred at 800 rpm for 12 h at 25 °C to prepare a silver-based gel electrolyte.

[0031] c) Two flexible transparent conductive electrodes are placed in a parallel staggered manner, with the indium tin oxide conductive layer on the inner side of the electrode and the polyethylene terephthalate (PET) substrate layer on the outer side. Both sides of the staggered electrodes are exposed 0.5 cm, and 3M VHB double-sided transparent adhesive with a thickness of 0.5 mm is used to bond the two electrodes, and a 0.1 mm wide injection gap is left during the bonding process.

[0032] d) A silver-based gel electrolyte is injected between two symmetrically offset and bonded transparent flexible conductive electrodes until the electrode gap is filled to form a three-layer structure of electrode-electrolyte-electrode.

[0033] e) The electrolyte injection port is encapsulated using UV curing glue (brand: MECHANIC) to obtain a flexible electrochromic device, wherein the polyethylene terephthalate-indium tin oxide layer has a thickness of 0.125 mm and the silver-based gel electrolyte has a thickness of 0.5 mm.

[0034] The optical properties of the device in the wavelength range of 0.3-2.5μm were characterized using an ultraviolet-visible near-infrared spectrometer (brand: Shimadzu, model: UV-3600i Plus). The test results show that the sunlight transmittance of the flexible electrochromic device in the initial solar heating state is 71.81%, and the sunlight reflectivity is 15.45%; after applying a pulse voltage of -2.5V using a waveform generator (brand: Agilent, model 33210A), a dense silver nanofilm (bright, high sunlight reflectivity) is deposited on the negative electrode. At this time, the device is in a radiation cooling state, and the device's sunlight reflectivity is 88.14%, and the sunlight transmittance is 0.08%.

[0035] The emissivity of the device in the wavelength range of 8-13 μm was tested using a Fourier transform infrared spectrometer (brand: Thermo Fisher Scientific, model Nicolet iS50). The average infrared emissivity of the outer layer of the flexible electrochromic device was 91.84%. Example 3

[0036] The flexible electrochromic device is prepared as follows: a) Using commercial polyethylene terephthalate-indium tin oxide electrodes (purchased from South China Xiangcheng Technology Co., Ltd., resistance 40 ohms, polyethylene terephthalate thickness 0.125 mm, indium tin oxide film thickness 55 nm), the electrode surface was cleaned and surface modified. The cleaning steps were ultrasonically cleaned with acetone, isopropanol, ethanol and deionized water for 10 minutes, and then dried at 60 ° C in a nitrogen atmosphere for 2 hours. Subsequently, oxygen plasma cleaning was performed for 10 minutes, and 3-mercaptopropyltrimethoxysilane was used for surface modification: the flexible transparent conductive electrode was immersed in a mixed solution of toluene / 3-mercaptopropyltrimethoxysilane (the volume ratio of 3-mercaptopropyltrimethoxysilane to toluene was 1:40) for 12 hours. Subsequently, ultrasonic treatment was performed in ethanol for 10 minutes to remove the residual unbound monomers on the electrode surface. Finally, the surface-modified electrode was dried at 60 ° C in a nitrogen atmosphere for 2 hours.

[0037] b) 0.17 g of silver nitrate, 0.026 g of copper chloride, and 1.612 g of tetrabutylammonium bromide were dissolved in 25 ml of dimethyl sulfoxide (DMSO), and 10% of polyvinyl butyral by mass of the total system was added, and the mixture was stirred magnetically at 800 rpm at 60°C for 12 h to prepare a silver-based gel electrolyte.

[0038] c) Two flexible transparent conductive electrodes are placed in parallel and staggered manner, with the indium tin oxide conductive layer on the inner side of the electrode and the polyethylene terephthalate (PET) substrate layer on the outer side. Both sides of the staggered electrodes are exposed for 1 cm, and 0.5 mm thick 3M VHB double-sided transparent adhesive is used to bond the two electrodes, leaving a 0.1 mm wide injection gap during the bonding process.

[0039] d) A silver-based gel electrolyte is injected between two symmetrically offset and bonded transparent flexible conductive electrodes until the electrode gap is filled to form a three-layer structure of electrode-electrolyte-electrode.

[0040] e) The electrolyte injection port is encapsulated using UV curing glue (brand: MECHANIC) to obtain a flexible electrochromic device, wherein the polyethylene terephthalate-indium tin oxide layer has a thickness of 0.125 mm and the silver-based gel electrolyte has a thickness of 0.5 mm.

[0041] The optical properties of the device in the wavelength range of 0.3-2.5μm were characterized using an ultraviolet-visible near-infrared spectrometer (brand: Shimadzu, model: UV-3600i Plus). The test results show that the sunlight transmittance of the flexible electrochromic device in the initial solar heating state is 73.25%, and the sunlight reflectivity is 14.71%; after applying a pulse voltage of -2.5V using a waveform generator (brand: Agilent, model 33210A), a dense silver nanofilm (bright, high sunlight reflectivity) is deposited on the negative electrode. At this time, the device is in a radiation cooling state, and the device's sunlight reflectivity is 86.50%, and the sunlight transmittance is 0.25%.

[0042] The emissivity of the device in the wavelength range of 8-13 μm was tested using a Fourier transform infrared spectrometer (brand: Thermo Fisher Scientific, model Nicolet iS50). The average infrared emissivity of the outer layer of the flexible electrochromic device was 92.30%. Example 4

[0043] The flexible electrochromic device is prepared as follows: a) A commercial polyethylene terephthalate-indium tin oxide electrode (purchased from South China Xiangcheng Technology Co., Ltd., with a resistance of 40 ohms, a polyethylene terephthalate thickness of 0.125 mm, and an indium tin oxide film thickness of 55 nm) was used without cleaning or modifying the electrode surface.

[0044] b) 0.17 g of silver nitrate, 0.026 g of copper chloride, and 1.612 g of tetrabutylammonium bromide were dissolved in 25 ml of dimethyl sulfoxide (DMSO), and 10% of polyvinyl butyral was added to the mixture, and the mixture was stirred at 800 rpm for 12 h at 25 °C to prepare a silver-based gel electrolyte.

[0045] c) Two flexible transparent conductive electrodes are placed in a parallel staggered manner, with the indium tin oxide conductive layer on the inner side of the electrode and the polyethylene terephthalate (PET) substrate layer on the outer side. Both sides of the staggered electrodes are exposed 0.5 cm, and 3M VHB double-sided transparent adhesive with a thickness of 0.5 mm is used to bond the two electrodes, and a 0.1 mm wide injection gap is left during the bonding process.

[0046] d) A silver-based gel electrolyte is injected between two symmetrically offset and bonded transparent flexible conductive electrodes until the electrode gap is filled to form a three-layer structure of electrode-electrolyte-electrode.

[0047] e) The electrolyte injection port is encapsulated using UV curing glue (brand: MECHANIC) to obtain a flexible electrochromic device, wherein the polyethylene terephthalate-indium tin oxide layer has a thickness of 0.125 mm and the silver-based gel electrolyte has a thickness of 0.5 mm.

[0048] The optical properties of the device in the wavelength range of 0.3-2.5μm were characterized using an ultraviolet-visible near-infrared spectrometer (brand: Shimadzu, model: UV-3600i Plus). The test results show that the solar transmittance of the flexible electrochromic device in the initial solar heating state is 68.95%, and the solar reflectivity is 15.62%; after applying a -2.5V pulse voltage using a waveform generator (brand: Agilent, model 33210A), the silver nanofilm deposited on the device appears black (low solar reflectivity and high absorptivity), the solar reflectivity of the device is 41.65%, and the solar transmittance is 9.67%.

[0049] The emissivity of the device in the wavelength range of 8-13 μm was tested using a Fourier transform infrared spectrometer (brand: Thermo Fisher Scientific, model Nicolet iS50). The average infrared emissivity of the outer layer of the flexible electrochromic device was 91.70%.

[0050] The device structure and the actual working status are shown in the figure below. Figure 1 As shown, Figure 1 Figure a shows the preparation process of the flexible electrochromic device in the form of a flow chart. Figure 1 Figure b is a schematic diagram of the three-layer symmetrical structure of the device. Figure 1 Figure c is a photo of the actual device prepared in Example 1 in two modes: radiation cooling and solar heating, demonstrating its ability for curved surface applications: by applying a pulse voltage of -2.5V, the device is in radiation cooling mode, with high solar reflectivity, and the reflection of the panda ornament on the front side can be clearly seen; when the applied voltage is removed, the device returns to solar heating mode, with high solar transmittance, and the image of the Southeast University logo behind the device can be clearly seen. Figure 1 Figure d in the figure shows a photograph of a bending change applied to the physical device prepared in Example 1 using a tensile testing machine (brand: Qingbo, model: QB-8106), with a bending radius of 25 mm. The device can repeatedly undergo reversible changes between the straight state and the bent state.

[0051] The flexible electrochromic device based on silver electroreversible deposition prepared by this method can realize all-season dynamic thermal management of curved transparent enclosure structures, effectively adjust the transmitted and reflected solar energy, and improve energy efficiency.

[0052] It should be noted that the above content merely illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A flexible electrochromic device for thermal management of curved transparent enclosure structures, comprising a flexible transparent conductive electrode, a silver-based gel electrolyte and a transparent packaging material, characterized in that: The flexible transparent conductive electrode is a polyethylene terephthalate-indium tin oxide electrode. The two flexible transparent conductive electrodes are placed in parallel and staggered, and are bonded and fixed by a transparent packaging material. A silver-based gel electrolyte is injected between the two flexible transparent conductive electrodes to form a three-layer structure of electrode-electrolyte-electrode.

2. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 1, characterized in that: The indium tin oxide surface of the flexible transparent conductive electrode is cleaned and surface modified, and the cleaning and surface modification treatment includes the following steps: ultrasonic cleaning with acetone, isopropanol, ethanol and deionized water for 10-15 minutes in sequence, and then drying at 60°C in a nitrogen atmosphere for 2-3 hours; then oxygen plasma cleaning for 10-15 minutes, and surface modification with 3-mercaptopropyltrimethoxysilane.

3. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 2, characterized in that: The surface modification using 3-mercaptopropyltrimethoxysilane includes the following steps: immersing the flexible transparent conductive electrode after oxygen plasma cleaning in a mixed solution of 3-mercaptopropyltrimethoxysilane and toluene with a volume ratio of 1:40 for 12 hours; then, ultrasonically treating it in ethanol for 10-15 minutes, and drying the surface-modified electrode at 60° C. in a nitrogen atmosphere for 2-3 hours.

4. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 1, characterized in that: The two transparent flexible conductive electrodes are placed in parallel, with indium tin oxide located on the inner side of the electrode and polyethylene terephthalate located on the outer side.

5. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 1, characterized in that: The two transparent flexible conductive electrodes are placed in a staggered manner, and both sides of the staggered electrodes are exposed by 0.5-1 cm.

6. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 5, characterized in that: A transparent packaging material with a thickness of 0.5 mm is used to bond the two offset transparent flexible conductive electrodes, and a liquid injection gap with a width of 0.1 mm is left during the bonding process.

7. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 6, characterized in that: The transparent packaging material is VHB closed-cell acrylic foam.

8. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 1, characterized in that: The silver-based gel electrolyte is prepared by dissolving silver nitrate, cupric chloride, tetrabutylammonium bromide and polyvinyl butyral in dimethyl sulfoxide, wherein the molar ratio of bromine, silver and copper is 25:5:1, and the ratio of the mass of dimethyl sulfoxide to the sum of the mass of silver nitrate, cupric chloride and tetrabutylammonium bromide is 15:1; then, 10% of the total mass of the system polyvinyl butyral is added, and the mixture is stirred and mixed at 25° C.-60° C. for 12 hours to gel the electrolyte to obtain the silver-based gel electrolyte.

9. The flexible electrochromic device for thermal management of curved transparent enclosure structure according to claim 6, characterized in that: After the silver-based gel electrolyte is injected through the injection gap, the injection gap is encapsulated using UV curing glue.

10. Application of a flexible electrochromic device for thermal management of curved transparent enclosure structures, characterized in that: The device is adhered to the surface of a curved transparent enclosure structure for use, and its reversible switching of radiation cooling / solar heating mode is controlled by applying / removing a -2.5V voltage to achieve dynamic thermal management.

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