Reversible metal electro-deposition variable-emissivity device based on multilayer film electrode and preparation method of reversible metal electro-deposition variable-emissivity device

Abstract

The invention discloses a reversible metal electrodeposition variable emissivity device based on a multilayer film electrode and a preparation method thereof, and relates to the technical field of electrochromism. A reversible metal electrodeposition variable emissivity device based on a multilayer film electrode comprises a flexible transparent multilayer film, an electrolyte and a bottom electrode. The flexible transparent multilayer film comprises a flexible transparent film substrate, a conductive layer, an infrared high-transmittance layer and a catalyst layer. According to the invention, a vacuum magnetron sputtering process is adopted to obtain a multi-layer metal composite film with high density and fine and uniform surface appearance, and then the multi-layer film electrode-based reversible metal electrodeposition variable emissivity device is assembled; and relatively, the conductivity of the thin film electrode is greatly improved due to the introduction of multiple layers of metal. The metal film with excellent performance is obtained through an optical performance test and an electrical performance test, a flexible electrochromic infrared device is assembled to analyze the optical modulation performance and the thermal control performance, and the excellent performance effect and the huge building energy-saving potential are shown.

Description

Technical Field

[0001] This invention relates to the field of electrochromic technology, specifically to a reversible metal electrodeposition variable emissivity device based on multilayer thin-film electrodes and its fabrication method. Background Technology

[0002] Over the past three decades, driven by factors such as power capacity expansion and economic and population growth in developing countries, the construction industry has become a core sector of global energy consumption and carbon emissions. Its energy consumption covers all aspects of construction, heating, and cooling, accounting for more than one-third of global total energy consumption and emissions. Among these, heating, ventilation, and air conditioning (HVAC) systems account for 40% of total building energy consumption, and demand is expected to continue to rise over the next two decades. Currently, static radiative cooling materials and low-emissivity building envelopes are limited by temporal and spatial weather variations, making them unsuitable for extreme weather conditions under global warming. Net-zero energy buildings with dynamic thermal emissivity regulation are becoming an inevitable trend. Electrochromic technology can actively regulate indoor heat and light according to environment and needs, providing key support for intelligent building thermal control. However, traditional electrochromic devices (ECDs) rely on complex and expensive manufacturing processes, and their light modulation and thermal management performance is limited, hindering commercialization. Reversible metal electrodeposition devices (RMEDs) overcome these bottlenecks by achieving photothermal synergistic modulation through electrochemical metal deposition / dissolution cycles. Their simplified architecture and support for solution manufacturing significantly reduce production difficulty. It adopts a sandwich configuration, using a highly transparent metal salt solution as the electrolyte, and adjusts optical properties through reversible deposition and dissolution of metal ions. Combined with the localized surface plasmon resonance effect of Ag nanoparticles, it possesses a wide range of color control capabilities, making it suitable for the "dual carbon" target in the field of building energy conservation and showing broad development prospects. Current research on reversible silver electrodeposition has mainly focused on improving the performance of reversible metal electrodeposition electrochromic devices, such as response speed (patent number: CN202510314668A), lacking optimization of the device's electrode structure. The main difficulty in applying reversible metal electrodeposition to achieve emissivity control lies in the design of the top electrode. For the emissivity control range in the 2.5-25 micrometer infrared band, the optical transmittance of the top electrode directly affects the overall control range of the device. In addition, the conductivity of the top electrode also directly affects the device's response time and cycle stability. Since metal particles are repeatedly deposited and dissolved directly on the contact surface of the top electrode, this also places requirements on the structure and surface energy of the electrode surface. Inventing a top electrode with excellent optical transmittance, good conductivity, and favorable surface properties is of great significance for the application of reversible metal electrodeposition devices in emissivity modulation. Liu Dongqing's team disclosed a flexible infrared radiation dynamic modulation device and its fabrication method (patent number: CN 113568197A), but their designed infrared radiation dynamic modulation device has limited emissivity modulation range, with a change of 0.46 in the 3-5 μm band and 0.33 in the 8-14 μm band. There is significant room for improvement in the modulation range to further expand the temperature control range.

[0003] In summary, the existing technology has the following technical problems:

[0004] (1) The optical and electrical properties as well as the surface properties of the top electrode cannot be simultaneously considered;

[0005] (2) The emissivity modulation range of flexible infrared modulation devices is limited. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a reversible metal electrodeposition variable emissivity device based on multilayer thin-film electrodes and its fabrication method.

[0007] This invention focuses on designing a top electrode for a multilayer metal thin film. Different metal layers have different effects to achieve a balance of excellent optical transmittance, good electrical conductivity, and good surface properties.

[0008] The flexible transparent multilayer thin film designed in this invention consists of four parts: a flexible transparent thin film substrate, a conductive layer, an infrared high-transmittance layer, and a catalytic layer. Multiple metal layers are sputtered onto the flexible transparent thin film substrate using magnetron sputtering technology. Different metals are used for different functional layers, and their sputtering process parameters are also different.

[0009] This invention employs vacuum magnetron sputtering to obtain multilayer metal composite thin films with high density and fine, uniform surface morphology. These films are then assembled into reversible metal electrodeposition variable emissivity devices based on multilayer thin film electrodes. The introduction of multilayer metals significantly enhances the conductivity of the thin film electrodes. Optical and electrical performance tests yielded high-performance metal thin films, which were then assembled into flexible electrochromic infrared devices to analyze their optical modulation and thermal control performance, demonstrating superior performance and significant potential for building energy conservation.

[0010] A reversible metal electrodeposition variable emissivity device based on multilayer thin film electrodes includes a flexible transparent multilayer thin film, an electrolyte, and a bottom electrode;

[0011] The flexible transparent multilayer film includes a flexible transparent film substrate, a conductive layer, an infrared high-transmittance layer, and a catalytic layer;

[0012] The flexible transparent film substrate is made of a material with an infrared transmittance greater than 60%.

[0013] The conductive layer is a metal layer with good electrical conductivity;

[0014] The aforementioned high-transmittance infrared layer is a metal layer with good optical transmittance in the 2.5-25 micrometer infrared band;

[0015] The catalyst layer is a metal layer with good optical transmittance in the 2.5-25 micrometer infrared band, and the catalyst layer and the infrared high transmittance layer are different metals;

[0016] The electrolyte is a gel electrolyte, which is prepared from a charge exchange medium salt, a supporting electrolyte salt, a host polymer, and a solvent;

[0017] The bottom electrode is PET-ITO or gold-plated nylon.

[0018] A method for fabricating a reversible metal electrodeposition variable emissivity device based on multilayer thin-film electrodes is specifically carried out according to the following steps:

[0019] 1. A conductive layer and an infrared high-transmittance layer are sequentially sputtered onto one surface of a flexible transparent thin film substrate using magnetron sputtering.

[0020] A flexible, transparent multilayer film is obtained by adding a catalyst layer and a catalyst layer.

[0021] 2. Add the charge exchange medium salt, the supporting electrolyte salt, and the main polymer to the solvent, stir until homogeneous, and obtain the electrolyte;

[0022] 3. A conductive layer is sputtered onto a flexible substrate using magnetron sputtering to obtain the bottom electrode;

[0023] 4. Cut the flexible transparent multilayer film, electrolyte, and bottom electrode to the same size, and then make the catalyst layer and electrolyte...

[0024] The gold layer on the bottom electrode comes into contact with the electrolyte, and then they are bonded together sequentially to obtain a multilayer structure.

[0025] 5. The above multilayer structure is encapsulated by hot pressing, and lead-out wire terminals are obtained to obtain a reversible metal electrodeposition variable emissivity device based on multilayer thin film electrodes.

[0026] The beneficial effects of this invention are:

[0027] (1) In view of the existing application of reversible metal deposition to optimize the design of the top electrode, this invention innovatively prepares a flexible metal thin film top electrode (flexible transparent multilayer film) with good conductivity, high infrared transmittance and good surface properties, effectively achieving a balance between good optical performance and electrical performance; through four-probe sheet resistance measurement, the sheet resistance of the electrode is less than 10Ω / , and the excellent conductivity is conducive to the reversible deposition of metal; Fourier transform infrared spectroscopy test shows that the infrared transmittance of the flexible metal thin film top electrode is as high as 89.33%.

[0028] (2) The flexible reversible Ag metal deposition device prepared by this invention exhibits significant electrochromic performance. Its emissivity in the low emissivity state in the 2.5-25 micrometer wavelength range is as low as 0.12, while its emissivity in the high emissivity state is as high as 0.92, with an emissivity modulation amplitude as high as 0.80, far exceeding most current electrochromic emissivity devices. Based on this high-amplitude emissivity modulation, the flexible reversible Ag metal deposition device demonstrates significant temperature control. Under a substrate heating state of 30 degrees Celsius, the high emissivity state temperature is 30.4℃, and the temperature switching to the low emissivity state is 16.2℃, achieving a temperature change exceeding 13℃.

[0029] (3) Compared to the inflexibility of conventional solid-state devices, the flexible reversible Ag metal deposition device prepared in this invention exhibits excellent flexibility and ductility. Mechanical tests show that after 500 consecutive bends, the electrochromic performance of the device degrades by only 2%. The device itself has good cycle stability; after 400 cycles, the electrochromic modulation amplitude decreases by only 3%. This indicates that the flexible reversible Ag metal deposition device has good stability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a reversible metal electrodeposition variable emissivity device based on multilayer thin film electrodes according to the present invention;

[0031] Figure 2 The infrared reflectance spectrum of the flexible reversible Ag metal deposition device prepared in Example 1 is shown below. The low-energy state curve is the infrared reflectance curve of the device when it switches to the deposition state by applying a negative 3V, and the high-energy state curve is the infrared reflectance curve of the device when it switches to the dissolution state by applying a positive 3V.

[0032] Figure 3 The infrared emissivity spectrum of the flexible reversible Ag metal deposition device prepared in Example 1;

[0033] Figure 4 Cyclic voltammetry curves of the flexible reversible Ag metal deposition device prepared in Example 1. Detailed Implementation

[0034] Specific implementation method one: This implementation method is a reversible metal electrodeposition variable emissivity device based on multilayer thin film electrodes, including a flexible transparent multilayer thin film, an electrolyte and a bottom electrode;

[0035] The flexible transparent multilayer film includes a flexible transparent film substrate, a conductive layer, an infrared high-transmittance layer, and a catalytic layer;

[0036] The flexible transparent film substrate is made of a material with an infrared transmittance greater than 60%.

[0037] The conductive layer is a metal layer with good electrical conductivity;

[0038] The aforementioned high-transmittance infrared layer is a metal layer with good optical transmittance in the 2.5-25 micrometer infrared band;

[0039] The catalyst layer is a metal layer with good optical transmittance in the 2.5-25 micrometer infrared band, and the catalyst layer and the infrared high transmittance layer are different metals;

[0040] The electrolyte is a gel electrolyte, which is prepared from a charge exchange medium salt, a supporting electrolyte salt, a host polymer, and a solvent;

[0041] The bottom electrode is PET-ITO or gold-plated nylon.

[0042] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the flexible transparent film substrate is a PI film or a PE film with a thickness of 6~8μm. Other steps are the same as in Specific Implementation Method One.

[0043] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the conductive layer is an Ag thin film, Cu thin film, Pt thin film, Au thin film, or Al thin film; the thickness of the conductive layer is 2~40nm. Other steps are the same as in Specific Implementation Method 1 or 2.

[0044] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the infrared high-transmittance layer is a Ge thin film, Si thin film, Ti thin film, or Pt thin film; the thickness of the infrared high-transmittance layer is 2~40nm. Other steps are the same as in Specific Implementation Methods One to Three.

[0045] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the catalyst layer is a Ge thin film, Si thin film, Ti thin film, or Pt thin film; the thickness of the catalyst layer is 2~40 nm. Other steps are the same as in Specific Implementation Methods One to Four.

[0046] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the charge exchange medium salt is silver bromide, silver chloride, copper chloride, decamethylferrocene, decamethylferrocene tetrafluoroborate, or (ferrocenemethyl)tri-tert-butyltetrafluoroborate ammonium salt; the supporting electrolyte salt is tetrabutylammonium bromide or tetramethylammonium bromide; the main polymer is polyvinyl butyral, polyvinyl alcohol, or polyethylene oxide; and the solvent is water, organic solvent, ionic liquid, polyionic liquid, or eutectic solvent. Other steps are the same as in Specific Implementation Methods One to Five.

[0047] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the concentration of the charge exchange medium salt in the gel electrolyte is 0.5 mol / L to 2 mol / L, the concentration of the supporting electrolyte salt is 0.5 mol / L to 2 mol / L, and the mass fraction of the main polymer is 10% to 15%. Other steps are the same as in Specific Implementation Methods One to Six.

[0048] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the organic solvent is one or a mixture of dimethyl sulfoxide and water; the ionic liquid is [BMIM][NTf2] or [BMIM][BF4]; the polyionic liquid is a polyvinyl imidazole or a polyionic liquid gel; and the eutectic solvent is ChCl-urea or ChCl-ethylene glycol. Other steps are the same as in Specific Implementation Methods One to Seven.

[0049] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: the thickness of the electrolyte is 1-3 mm; the thickness of the PET on the PET-ITO is 0.1-0.2 mm; and the thickness of the gold layer on the gold-plated nylon layer is 200-400 nm. Other steps are the same as in Specific Implementation Methods One to Eight.

[0050] Specific Implementation Method Ten: This implementation method is a fabrication method for a reversible metal electrodeposition variable emissivity device based on multilayer thin-film electrodes, specifically completed according to the following steps:

[0051] 1. A flexible transparent multilayer film is obtained by sequentially sputtering a conductive layer, an infrared high-transmittance layer, and a catalytic layer on one surface of a flexible transparent thin film substrate using a magnetron sputtering method.

[0052] 2. Add the charge exchange medium salt, the supporting electrolyte salt, and the host polymer to the solvent, stir until homogeneous, and obtain the electrolyte:

[0053] 3. A conductive layer is sputtered onto a flexible substrate using magnetron sputtering to obtain the bottom electrode;

[0054] 4. Cut the flexible transparent multilayer film, electrolyte and bottom electrode to the same size, then make the catalyst layer and electrolyte in contact, and the gold layer on the bottom electrode in contact with the electrolyte, and then bond them together in sequence to obtain a multilayer structure.

[0055] 5. The above multilayer structure is encapsulated by hot pressing, and lead-out wire terminals are obtained to obtain a reversible metal electrodeposition variable emissivity device based on multilayer thin film electrodes.

[0056] The beneficial effects of the present invention are verified using the following embodiments:

[0057] Example 1: A flexible reversible Ag metal deposition device includes a flexible transparent multilayer thin film, an electrolyte, and a bottom electrode; the flexible transparent multilayer thin film includes a flexible transparent thin film substrate, a conductive layer, an infrared high-transmittance layer, and a catalytic layer, and the preparation method is specifically carried out according to the following steps:

[0058] 1. A flexible, transparent multilayer film is obtained by sequentially sputtering a conductive layer, an infrared high-transmittance layer, and a catalytic layer on one surface of a polyethylene film (PE, size 40×40mm) using a magnetron sputtering method.

[0059] The conductive layer mentioned in step one is an Ag thin film with a thickness of 20 nm;

[0060] The infrared high-transmittance layer mentioned in step one is a Ge thin film with a thickness of 20 nm;

[0061] The catalyst layer mentioned in step one is a Pt thin film with a thickness of 5 nm;

[0062] 2. Add silver bromide (AgBr), tetrabutylammonium bromide (TBABr), and polyvinyl butyral (PVB) to dimethyl sulfoxide (DMSO), stir until homogeneous, and obtain the electrolyte:

[0063] In step two, the electrolyte contains silver bromide (AgBr) at a concentration of 0.5 mol / L, tetrabutylammonium bromide (TBABr) at a concentration of 0.5 mol / L, and polyvinyl butyral (PVB) at a mass fraction of 10%.

[0064] 3. A 200 nm gold layer was sputtered onto flexible nylon using magnetron sputtering to obtain the bottom electrode;

[0065] 4. Cut the flexible transparent multilayer film, electrolyte and bottom electrode to the same size, then make the catalyst layer and electrolyte in contact, and the gold layer on the bottom electrode in contact with the electrolyte, and then bond them together in sequence to obtain a multilayer structure.

[0066] The bottom electrode mentioned in step four is gold-plated nylon, and the preparation method is as follows: a 200nm thick Au layer is deposited on the nylon substrate by magnetron sputtering.

[0067] Fifth, the above multilayer structure is encapsulated by hot pressing. Then, gold electrode sheets are added to the edges of the conductive layer and the bottom electrode to enhance the conductivity of the electrodes and serve as wire terminals for connection with external circuits, thus obtaining a flexible reversible metal Ag deposition device, which is a reversible metal electrodeposition variable emissivity device based on multilayer thin film electrodes.

[0068] Figure 2The infrared reflectance spectrum of the flexible reversible Ag metal deposition device prepared in Example 1 is shown below. The low-activity curve is the infrared reflectance curve of the device when it switches to the deposition state by applying a negative 3V, and the high-activity curve is the infrared reflectance curve of the device when it switches to the dissolution state by applying a positive 3V.

[0069] from Figure 2 It can be seen that after applying a -3V reverse voltage, silver particles are deposited on the surface of the device after 20 seconds (from electrolyte deposition to flexible transparent multilayer film). The deposition of silver increases the infrared reflectivity, and the device switches to a low-emission state. At this time, the infrared reflectivity of the device increases significantly, fluctuating around 0.8-0.9. After applying a +3V reverse voltage, the silver particles dissolve, and the reflectivity of the device in the infrared band decreases, switching to a high-emission state. At this time, the reflectivity range is around 0.1-0.2.

[0070] Figure 3 The infrared emissivity spectrum of the flexible reversible Ag metal deposition device prepared in Example 1;

[0071] from Figure 3 It can be seen that the blackbody radiation curve represents a blackbody radiation reference with an emissivity of 1. The high emissivity state is the infrared emissivity curve of the device when negative 3V is applied to deposit metal, showing a high emissivity state. The low emissivity curve is the infrared emissivity curve of the device when positive 3V is applied to dissolve metal and switch to a low emissivity state.

[0072] After applying a -3V reverse voltage and depositing metallic silver for 20 seconds (from electrolyte deposition to a flexible transparent multilayer film), the infrared reflectivity of the reversible electrodeposited device changes significantly. Silver particles deposit on the surface, causing the device to switch to a high-emission state, at which point the infrared reflectivity increases dramatically to 0.92. Applying a +3V reverse voltage causes the silver particles to dissolve, resulting in a decrease in the device's reflectivity in the infrared band, switching to a low-emission state. At this point, the reflectivity amplitude is 0.12, and the emissivity modulation amplitude reaches as high as 0.80.

[0073] Figure 4 Cyclic voltammetry curves of the flexible reversible Ag metal deposition device prepared in Example 1;

[0074] By applying a voltage of ±4.0V to the flexible reversible Ag metal deposition device prepared in Example 1, its cyclic voltammetry curve can be obtained.

Claims

1. A reversible metal electrodeposition of pattern transfer device based on multilayer thin film electrodes, characterized in that The flexible transparent multilayer film, electrolyte and bottom electrode are included. The flexible transparent multilayer film includes a flexible transparent film substrate, a conductive layer, an infrared high-transmittance layer and a catalytic layer. The flexible transparent film substrate is prepared from a material with an infrared transmittance of more than 60%. The conductive layer is a metal layer with good conductive performance. The infrared high-transmittance layer is a metal layer with good optical transmittance in the 2.5-25 micron infrared wave band. The catalytic layer is a metal layer with good optical transmittance in the 2.5-25 micron infrared wave band, and the catalytic layer and the infrared high-transmittance layer are different metals. The electrolyte is a gel electrolyte prepared from a charge exchange medium salt, a supporting electrolyte salt, a main polymer and a solvent. The bottom electrode is a PET-ITO or a gold-plated nylon layer.

2. A reversible metal electrodeposition of pattern transfer device based on multilayer thin film electrodes according to claim 1, characterized in that The flexible transparent film substrate is a PI film or a PE film with a thickness of 6-8 microns.

3. A reversible metal electrodeposition of pattern (MEP) variable emittance device based on multilayer thin film electrodes according to claim 1, wherein The conductive layer is an Ag film, a Cu film, a Pt film, an Au film or an Al film, and the thickness of the conductive layer is 2-40 nm.

4. A reversible metal electrodeposition of pattern (MEP) variable emittance device based on multilayer thin film electrodes according to claim 1, wherein The infrared high-transmittance layer is a Ge film, a Si film, a Ti film or a Pt film, and the thickness of the infrared high-transmittance layer is 2-40 nm.

5. A reversible metal electrodeposition of pattern (MEP) variable emittance device based on multilayer thin film electrodes as claimed in claim 1, wherein The catalytic layer is a Ge film, a Si film, a Ti film or a Pt film, and the thickness of the catalytic layer is 2-40 nm.

6. A reversible metal electrodeposition of pattern (MEP) variable emittance device based on multilayer thin film electrodes as claimed in claim 1, wherein The charge exchange medium salt is silver bromide, silver chloride, copper chloride, decamethyl ferrocene, decamethyl tetrafluoroboric acid ferrocene salt or (ferrocene methyl) tri-tert-butyl ammonium tetrafluoroborate; the supporting electrolyte salt is tetrabutylammonium bromide or tetramethylammonium bromide; the main polymer is polyvinyl butyral, polyvinyl alcohol or polyethylene oxide; and the solvent is water, an organic solvent, an ionic liquid, a polyionic liquid or a deep eutectic solvent.

7. A reversible metal electrodeposition of pattern (MEP) variable emittance device based on multilayer thin film electrodes as claimed in claim 1, wherein The concentration of the charge exchange medium salt in the gel electrolyte is 0.5-2 mol / L, the concentration of the supporting electrolyte salt is 0.5-2 mol / L, and the mass fraction of the main polymer is 10-15%.

8. A reversible metal electrodeposition of pattern (EMEP) variable emittance device based on multilayer thin film electrodes as claimed in claim 6, wherein The organic solvent is a mixture of one or both of dimethyl sulfoxide and water; the ionic liquid is [BMIM][NTf2] or [BMIM][BF4]; the polyionic liquid is a polyvinylimidazole or a polyionic liquid gel; and the deep eutectic solvent is ChCl-urea or ChCl-ethylene glycol.

9. A reversible metal electrodeposition of pattern (MEP) variable emittance device based on multilayer thin film electrodes as claimed in claim 1, wherein The thickness of the electrolyte is 1-3 mm; the thickness of the PET on the PET-ITO is 0.1-0.2 mm; and the thickness of the gold layer on the gold-plated nylon layer is 200-400 nm.

10. The method for fabricating a reversible metal electrodeposition variable emissivity device based on multilayer thin-film electrodes as described in claim 1, characterized in that... The preparation method is specifically completed according to the following steps: I. A flexible transparent multilayer film is obtained by sequentially sputtering a conductive layer, an infrared high-transmittance layer and a catalytic layer on one surface of a flexible transparent film substrate by a magnetron sputtering method; II. An electrolyte is obtained by adding a charge exchange medium salt, a supporting electrolyte salt and a main polymer into a solvent and stirring uniformly; III. A bottom electrode is obtained by sputtering a conductive layer on a flexible substrate by a magnetron sputtering method. Four, the flexible transparent multilayer film, electrolyte and bottom electrode are cut into the same size, then the catalytic layer and electrolyte are contacted, the gold layer on the bottom electrode is contacted with the electrolyte, and then the lamination is sequentially carried out, to obtain a multilayer structure; Five, the packaging of the above multilayer structure is completed by a hot pressing method, the lead terminals are led out, and a reversible metal electrodeposition variable emissivity device based on a multilayer film electrode is obtained.

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