All-solid-state flexible electric infrared emissivity modulation device and preparation method thereof

Abstract

The application relates to the technical field of infrared radiation regulation, in particular to a full-solid-state flexible electric infrared emissivity regulation device and a preparation method thereof. The full-solid-state flexible electric infrared emissivity regulation device comprises, in sequence, a conductive layer, an ionic gel electrolyte layer which is hot-pressed and solidified on the conductive layer, and a multi-walled carbon nanotube layer which is hot-pressed and solidified on the ionic gel electrolyte layer; wherein the ionic gel electrolyte layer is composed of a polymer matrix and an ionic liquid, the ionic liquid contains imidazole cations and bis-trifluoromethanesulfonylimide anions, the multi-walled carbon nanotube layer has a three-dimensional porous network structure, and the polymer matrix in the ionic gel electrolyte layer penetrates into the three-dimensional porous network structure. The device of the application has the comprehensive advantages of high ionic conductivity, low interface resistance, large modulation amplitude, fast response, excellent cycle stability and self-supporting flexibility while avoiding liquid leakage.

Description

Technical Field

[0001] This application relates to the field of infrared radiation modulation technology, specifically to an all-solid-state flexible electro-induced infrared emissivity modulation device and its fabrication method. Background Technology

[0002] Infrared emissivity modulation technology has significant application value in fields such as infrared stealth, intelligent thermal management, spacecraft thermal control, and personal thermal comfort regulation. Traditional infrared emissivity modulation devices mostly employ rigid substrates and liquid or gel electrolyte systems, altering the radiation properties of the surface material through electrochemical or thermal methods.

[0003] However, existing infrared emissivity modulation devices suffer from the following problems in practical applications: First, when using liquid ionic liquids as electrolytes, electrolyte leakage is highly likely to occur during bending, folding, or long-term use, leading to device failure. Second, while existing solid or quasi-solid electrolytes can alleviate the leakage problem, they generally suffer from defects such as low ionic conductivity and poor contact with the electrode layer interface, resulting in limited infrared emissivity modulation range (typically Δε < 0.3) and long response time (several seconds to tens of seconds). Summary of the Invention

[0004] The purpose of this invention is to provide an all-solid-state flexible electro-infrared emissivity modulation device that, while avoiding liquid leakage, also possesses the combined advantages of high ionic conductivity, low interface resistance, large modulation amplitude, fast response, excellent cycle stability, and self-supporting flexibility.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an all-solid-state flexible electro-induced infrared emissivity modulation device, comprising, in sequence: Conductive layer; An ion gel electrolyte layer is hot-pressed and cured onto the conductive layer. Multi-walled carbon nanotube layers are hot-pressed and solidified onto the ion gel electrolyte layer; The ion gel electrolyte layer is composed of a polymer matrix and an ionic liquid. The ionic liquid contains imidazole cations and bis(trifluoromethanesulfonyl)imide anions. The multi-walled carbon nanotube layer has a three-dimensional porous network structure. The polymer matrix in the ion gel electrolyte layer permeates into the three-dimensional porous network structure.

[0006] Furthermore, in the ionogel electrolyte layer, the mass ratio of the ionic liquid to the polymer matrix is ​​33% to 90%.

[0007] Furthermore, the polymer matrix is ​​selected from one or more of thermoplastic polyurethane, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or polymethyl methacrylate.

[0008] Furthermore, the imidazole cation is selected from one or more of 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, or 1-propyl-3-methylimidazolium cation.

[0009] Furthermore, the conductive layer is a metal foil, a metal film, or a conductive carbon film.

[0010] Furthermore, the multi-walled carbon nanotube layer is a multi-walled carbon nanotube film, a single-walled carbon nanotube film, or a carbon nanotube array.

[0011] Furthermore, the all-solid-state flexible electro-infrared emissivity modulation device is a planar thin film.

[0012] This application also provides a method for fabricating the above-mentioned all-solid-state flexible electro-induced infrared emissivity modulation device, characterized in that it includes: An ion gel electrolyte layer, a conductive layer, and a multi-walled carbon nanotube layer are provided. The ion gel electrolyte layer is composed of a polymer matrix and an ionic liquid, wherein the ionic liquid contains imidazole cations and bis(trifluoromethanesulfonyl)imide anions. The conductive layer, the ion gel electrolyte layer, and the multi-walled carbon nanotube layer are stacked sequentially and then subjected to hot-press curing treatment to allow the polymer matrix in the ion gel electrolyte layer to penetrate into the three-dimensional porous network structure of the multi-walled carbon nanotube layer.

[0013] Furthermore, in the ionogel electrolyte layer, the mass ratio of the ionic liquid to the polymer matrix is ​​between 33% and 90%.

[0014] Furthermore, the method also includes: The polymer matrix is ​​dissolved in an organic solvent and stirred at a first temperature to obtain a precursor solution; An ionic liquid is added to the precursor solution to form a mixed solution; The temperature of the mixed liquid is adjusted to a second temperature, stirring is continued, and ultrasonic oscillation is applied to obtain a homogenized ion gel mixture.

[0015] The polymer matrix is ​​selected from one or more of thermoplastic polyurethane, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or polymethyl methacrylate; the ionic liquid is selected from one or more of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, or 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide; and the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or tetrahydrofuran.

[0016] The beneficial effects of this invention are as follows: First, the ionogel electrolyte layer consists of a polymer matrix and an ionic liquid. The polymer matrix acts as a three-dimensional network framework, confining the ionic liquid within it. This prevents the cations and anions from flowing macroscopically, thus preventing leakage even when the device is cut or bent. Simultaneously, the multi-walled carbon nanotube layer possesses a three-dimensional porous network structure. Hot-press curing softens the polymer matrix and allows it to penetrate into this porous network. Upon cooling, a continuous, seamless solid-solid interlocking interface is formed, further sealing the channels for ionic liquid leakage along the interlayer interfaces and eliminating the risk of leakage. Furthermore, hot-press curing fuses the conductive layer, ionogel electrolyte layer, and multi-walled carbon nanotube layer into an integrated stack, enhancing interlayer bonding and eliminating macroscopically separable interfaces. This effectively prevents interlayer separation, increased interfacial resistance, and electrolyte leakage during repeated bending or long-term electrochemical cycling, achieving excellent fatigue resistance. Additionally, due to the excellent film-forming properties and mechanical strength of the polymer matrix itself, the ionogel layer can form an independent film and is self-supporting, requiring no additional substrate, facilitating processing and integration.

[0017] Secondly, the combination of polymer matrix and ionic liquid in the ionogel electrolyte layer ensures rapid ion migration under an electric field; while the polymer-permeable interlocking structure formed by hot-pressing transforms the original two-dimensional physical contact into a three-dimensional interwoven interface, significantly reducing interfacial resistance and increasing the effective area for ion implantation. The synergistic effect of high ionic conductivity and low interfacial resistance enables voltage-driven ions to be rapidly and massively injected into the carbon nanotube layer, deeply modulating its free carrier concentration, thereby achieving a significant reversible change in infrared emissivity.

[0018] In summary, the device of this application not only avoids liquid leakage but also has the combined advantages of high ionic conductivity, low interface resistance, large modulation amplitude, fast response, excellent cycle stability, and self-supporting flexibility.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an all-solid-state flexible electro-induced infrared emissivity modulation device according to an embodiment of this application; Figure 2 This is a flowchart illustrating a method for fabricating an all-solid-state flexible electro-induced infrared emissivity modulated device according to an embodiment of this application; Figure 3 This is a schematic diagram illustrating the working mechanism of an all-solid-state flexible electro-induced infrared emissivity modulation device provided in an embodiment of this application; Figure 4 An electrochemical impedance spectroscopy (EIS) spectrum of an ion gel (IG) provided in an embodiment of this application. Figure 5 This application provides a surface temperature variation diagram of a device assembled from different ion gels under different applied voltages, as shown by an infrared thermal imager, for one embodiment of the present application. Figure 6 The response time curve of an all-solid-state flexible electro-induced infrared emissivity modulation device provided in an embodiment of this application; Figure 7 A pseudo-color image of the cooling process of an all-solid-state flexible electro-infrared emissivity modulation device provided in an embodiment of this application under an infrared thermal imager; Figure 8 Cyclic stability test diagram of an all-solid-state flexible electro-induced infrared emissivity modulation device provided in an embodiment of this application.

[0021] Figure labels: 1. Multi-walled carbon nanotube layer; 2. Ion gel electrolyte layer; 3. Conductive layer. Detailed Implementation

[0022] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1 The all-solid-state flexible electro-induced infrared emissivity modulation device shown in one embodiment of this application can be a planar thin film, comprising a conductive layer 3, an ion gel electrolyte layer 2 hot-pressed onto the conductive layer 3, and a multi-walled carbon nanotube layer 1 hot-pressed onto the ion gel electrolyte layer 2. The conductive layer 3, the ion gel electrolyte layer 2, and the multi-walled carbon nanotube layer 1 are arranged in a sequentially stacked manner. The ion gel electrolyte layer 2 is composed of a polymer matrix and an ionic liquid, the ionic liquid containing imidazole cations and bis(trifluoromethanesulfonyl)imide anions. The multi-walled carbon nanotube layer 1 has a three-dimensional porous network structure, and the polymer matrix within the ion gel electrolyte layer 2 permeates into the three-dimensional porous network structure.

[0024] First, the ionogel electrolyte layer 2 is composed of a polymer matrix and an ionic liquid. The polymer matrix serves as a three-dimensional network framework, confining the ionic liquid within it. This prevents the cations and anions from flowing macroscopically, thus preventing leakage even if the device is cut or bent. Simultaneously, the multi-walled carbon nanotube layer 1 possesses a three-dimensional porous network structure. Hot-press curing softens the polymer matrix and allows it to penetrate into this porous network. Upon cooling, the interlocking effect of the polymer chains and the strong van der Waals forces between the carbon materials work synergistically to create a stable and highly bonded solid-solid interlocking interface, further sealing the channels for ionic liquid leakage along the interlayer interface and eliminating the risk of leakage. Furthermore, hot-press curing fuses the conductive layer 3, ionogel electrolyte layer 2, and multi-walled carbon nanotube layer 1 into an integrated stack, enhancing interlayer bonding and eliminating macroscopically separable interfaces. This effectively prevents interlayer separation, increased interfacial resistance, and electrolyte leakage during repeated bending or long-term electrochemical cycling, achieving excellent fatigue resistance. Subsequent experiments showed that the infrared tuning performance of the device remained close to 86.6% after 2000 charge-discharge cycles. In addition, due to the good film-forming properties and mechanical strength of the polymer matrix itself, the ionogel layer can form a film independently and is self-supporting, without the need for an additional substrate, which facilitates processing and integration.

[0025] Secondly, the combination of polymer matrix and ionic liquid in the ionogel electrolyte layer 2 ensures rapid ion migration under an electric field; while the polymer-permeable interlocking structure formed by hot-pressing and curing transforms the original two-dimensional physical contact into a three-dimensional interwoven interface, significantly reducing interfacial resistance and increasing the effective area for ion implantation. The synergistic effect of high ionic conductivity and low interfacial resistance enables voltage-driven ions to be rapidly and massively implanted into the carbon nanotube layer, deeply modulating its free carrier concentration, thereby achieving a large and reversible change in infrared emissivity. In subsequent experiments, under a driving voltage of ±4V, the device's infrared emissivity modulation amplitude Δε reached as high as 0.1~0.7, the surface apparent temperature could be reduced from 36.2℃ to 21.3℃, and the dynamic response time was only 0.93 seconds.

[0026] Therefore, this device not only avoids liquid leakage, but also has the combined advantages of high ionic conductivity, low interface resistance, large modulation amplitude, fast response, excellent cycle stability and self-supporting flexibility.

[0027] It should be noted that, Figure 1 To represent the conductive layer 3, ionogel electrolyte layer 2, and multi-walled carbon nanotube layer 1, solid lines are used to distinguish the layers. However, in reality, due to the softening of the polymer matrix during hot-pressing and curing, it penetrates into the three-dimensional porous network of the multi-walled carbon nanotube layer 1. Upon cooling, this forms a solid-solid interface with interlocking polymer chains. Therefore, there are no clear physical boundaries between the layers; instead, they present an integrated, layered structure with interpenetrating and continuous transitions. Figure 1 The solid lines in the diagram are drawn only for ease of understanding and differentiation of the functional layers and do not represent the existence of separable macroscopic interfaces in the actual device.

[0028] In the ionogel electrolyte layer 2, the mass ratio of the ionic liquid to the polymer matrix is ​​33%–90%, specifically 33%, 45%, 50%, 66%, 70%, 80%, and 90%. Experiments show that this range achieves an optimal balance between ionic conductivity and mechanical flexibility. If the proportion of ionic liquid is too low, the ionic conductivity is insufficient, resulting in a longer response time; if the proportion is too high, the gel strength decreases, and the film-forming properties deteriorate.

[0029] The polymer matrix can form a stable solid gel with ionic liquids, and has good film-forming properties, flexibility and electrochemical stability. In an alternative embodiment, the polymer matrix is ​​selected from one or more of thermoplastic polyurethane (TPU), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polyethylene oxide (PEO) or polymethyl methacrylate (PMMA), wherein thermoplastic polyurethane is the most preferred due to its excellent elasticity and affinity for carbon nanotubes.

[0030] Imidazole cations possess low viscosity, high ion mobility, and a wide electrochemical window. When combined with bis(trifluoromethanesulfonyl)imide anions, they enable rapid electrochemical doping / dedoping processes, shortening response time. In an alternative embodiment, the imidazole cation is selected from one or more of 1-ethyl-3-methylimidazolium cations (EMIm), 1-butyl-3-methylimidazolium cations (BMIm), 1-hexyl-3-methylimidazolium cations (HMIm), or 1-propyl-3-methylimidazolium cations (PMIm).

[0031] To ensure good conductivity and thermo-press bonding with the ion gel electrolyte layer 2, in an alternative embodiment, the conductive layer 3 is a metal foil, a metal film, or a conductive carbon film, wherein copper foil is preferred due to its good affinity with thermoplastic polyurethane and low cost.

[0032] The multi-walled carbon nanotube layer 1 has a natural three-dimensional porous network, which can serve as an infrared emissivity modulation layer (by changing the carrier concentration through ion doping) and provide physical space for the penetration of the polymer matrix, forming an interlocking interface. In an alternative embodiment, the multi-walled carbon nanotube layer 1 is a multi-walled carbon nanotube film (MWCNT), a single-walled carbon nanotube film (SWCNT), or a carbon nanotube array (CNT array), with multi-walled carbon nanotube film (MWCNT) being preferred.

[0033] Figure 2A method for fabricating the aforementioned all-solid-state flexible electro-induced infrared emissivity modulated device is presented. This method achieves an interlocking interface between the ion-gel electrolyte layer 2 and the carbon nanotube layer by sequentially stacking an ion-gel electrolyte layer 2, a conductive layer 3, and a multi-walled carbon nanotube layer 1, followed by hot-pressing curing. This eliminates the need for liquid electrolytes or additional binders, resulting in a simple process suitable for mass production. The method specifically includes: S10, providing an ion gel electrolyte layer 2, a conductive layer 3, and a multi-walled carbon nanotube layer 1. The ion gel electrolyte layer 2 is composed of a polymer matrix and an ionic liquid, and the ionic liquid contains imidazole cations and bis(trifluoromethanesulfonyl)imide anions. S20. The conductive layer 3, the ion gel electrolyte layer 2, and the multi-walled carbon nanotube layer 1 are stacked sequentially and then subjected to hot-press curing treatment so that the polymer matrix in the ion gel electrolyte layer 2 can penetrate into the three-dimensional porous network structure of the multi-walled carbon nanotube layer 1.

[0034] In step S10 above, the mass ratio of the ionic liquid to the polymer matrix is ​​between 33% and 90%, specifically 33%, 45%, 50%, 66%, 70%, 80%, and 90%. By selecting this mass ratio range, the prepared ionic gel is ensured to possess both high ionic conductivity and mechanical strength, thereby achieving excellent infrared modulation performance in the final device. The polymer matrix is ​​selected from one or more of thermoplastic polyurethane (TPU), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polyethylene oxide (PEO), or polymethyl methacrylate (PMMA), and the ionic liquid is selected from 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([EMIm][ ]), 1-Butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ([BMIm][ ]) or 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ([HMIm][ One or more of the following are used: N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), or tetrahydrofuran (THF).

[0035] Before step S10 above, the process further includes fabricating an ion gel electrolyte layer 2, the method for fabricating the ion gel electrolyte layer 2 including: The polymer matrix is ​​dissolved in an organic solvent and stirred at a first temperature to obtain a precursor solution; An ionic liquid is added to the precursor solution to form a mixed solution; The temperature of the mixed liquid was adjusted to the second temperature, and stirring was continued, supplemented by ultrasonic oscillation treatment to obtain a homogenized ion gel mixture.

[0036] In practice, the first temperature can be 70~80℃, specifically 70℃, 75℃, or 80℃, and the stirring reaction time is 24~72 hours, specifically 24 hours, 36 hours, 54 hours, or 72 hours; the second temperature is 50~60℃, specifically 50℃, 55℃, or 60℃, and the stirring time is 1~3 hours, specifically 1 hour, 2 hours, or 3 hours.

[0037] The following examples illustrate the above-mentioned devices and their fabrication methods.

[0038] Example 1:

[0039] The device comprises a 18 μm copper foil, a 100 μm ion gel electrolyte layer 2, and a 30 μm multi-walled carbon nanotube film, which are sequentially hot-pressed, cured, and stacked.

[0040] The fabrication method of this device includes: Step 1: Preparation of ion gel mixture TPU was added to DMF solvent as a polymer matrix and placed in a constant temperature water bath at 70°C. The mixture was continuously stirred with magnetic force at a constant speed for 48 hours to completely dissolve the TPU and obtain a homogeneous precursor solution. [Emim][] was slowly added dropwise to the above precursor solution using a micropipette. ], control [Emim][ The mass ratio of the ionic liquid to TPU is 33%. After the addition is complete, the temperature of the mixed solution is lowered to 50°C, and the mixture is stirred at a constant temperature for 2 hours. At the same time, ultrasonic oscillation is applied to completely eliminate the tiny bubbles generated inside the solution, so as to achieve the monodispersity of the ionic liquid in the polymer matrix, suppress its tendency to agglomerate, and thus allow the polymer network to uniformly encapsulate the ions, resulting in a homogenized ionic gel mixture.

[0041] Step 2: Fabrication of ionogel films (IG) Iongel films were prepared using a spin-coating process. The iongel mixture from step 1 was uniformly coated onto a clean glass substrate, and the thickness, macroscopic flatness, and thickness uniformity of the liquid film were precisely controlled by centrifugal force. After spin-coating, the substrate with the wet film was transferred to a vacuum drying oven and continuously dried at 60°C for 48 hours to allow the DMF solvent to evaporate slowly and completely. After drying, the film was peeled off from the substrate to obtain a uniform, transparent, and self-supporting flexible iongel film (i.e., the subsequent iongel electrolyte layer 2).

[0042] Step 3: Assemble the components A sandwich structure is formed by sequentially stacking copper foil (Cu), flexible ionogel film (IG), and multi-walled carbon nanotube film (MWCNT). The stacked assembly is placed in a hot press and cured under suitable temperature (60°C) and pressure. During the hot pressing process, the TPU in the ionogel softens and macroscopically flows, spontaneously penetrating into the three-dimensional porous network of MWCNT. After cooling to room temperature, the polymer segments interact strongly with the carbon material due to interlocking effects, creating a stable and highly adherent solid-solid interface between the ionogel electrolyte layer 2 and the multi-walled carbon nanotube layer 1, ultimately yielding an all-solid-state flexible electro-infrared emissivity modulated device.

[0043] Example 2:

[0044] The difference between Example 2 and Example 1 is that in the preparation of the ion gel mixture in step one, TPU was added to DMF solvent as the polymer matrix and placed in a constant temperature water bath at 80°C. The reaction was carried out continuously for 24 hours with constant magnetic stirring. [Emim][ The mass ratio of the solution to TPU is 90%. After the addition is complete, the temperature of the mixed solution is lowered to 60°C, and the mixture is stirred at a constant temperature for 1 hour.

[0045] Example 3:

[0046] The difference between Example 3 and Examples 1 and 2 is that: 25μm copper foil, 200μm ion gel electrolyte layer 2 and 60μm multi-walled carbon nanotube film.

[0047] Example 4:

[0048] The difference between Example 4 and Examples 1-3 is that conductive carbon film and SWCNT are used instead of copper foil and multi-walled carbon nanotube film.

[0049] Example 5:

[0050] The difference between Example 5 and Examples 1-4 is that PVDF-HFP was added to the DMA solvent as the polymer matrix, and [HMIm][] was slowly added dropwise to the precursor solution. ], control [HMIm][ The mass ratio of PVDF-HFP is 45%.

[0051] Figure 3 A schematic diagram illustrating the working mechanism of the all-solid-state flexible electro-induced infrared emissivity modulation device provided in Example 1 is shown. As shown, when a positive bias is applied between the top multi-walled carbon nanotube film (MWCNT) and the bottom copper foil electrode, [Emim] in the ionogel (IG)... + Cations and [ ] - Anions migrate towards the two poles respectively. Among them, [Emim] + Cations are injected into the MWCNT layer under an electric field, altering the concentration of free carriers (electrons / holes) in the MWCNT through a reversible electrochemical doping process, thereby regulating the emissivity of the MWCNT in the mid-to-far infrared band (2.5–14 μm). When the voltage is removed or reversed, the ions are de-intercalated from the MWCNT layer, and the emissivity returns to its initial state. This mechanism enables dynamic and reversible control of infrared emissivity.

[0052] Figure 4 The electrochemical impedance spectroscopy (EIS) spectrum of the ionogel (IG) provided in Example 1 is shown. The tests were performed at room temperature using a two-electrode system on an electrochemical workstation (CHI660), with a frequency range of 10 Hz. 5 The frequency range is Hz to 0.1 Hz, with an AC perturbation voltage of 10 mV. The figure shows the Nyquist curves, indicating that the semicircle in the high-frequency region corresponds to the bulk impedance of the ion gel, and the value at its intersection with the real axis is the bulk resistance of the system; the straight line in the low-frequency region reflects the diffusion behavior of ions at the electrode interface. The ionic conductivity of the ion gel can be calculated through fitting. The results show that the ion gel provided in this application has high ionic conductivity (typical value >10 Hz). -3 With a range of S / cm and a wide electrochemical stability window (≥3.8 V), it meets the electrolyte requirements for solid-state flexible devices.

[0053] Figure 5 The figure shows the surface temperature changes of devices assembled from different ionomers under different applied voltages, as provided in Example 1, under an infrared thermal imager. During testing, the devices were placed on a constant-temperature hot stage (simulating human skin temperature of approximately 36-37°C), and different bias voltages (0 V, ±2 V, ±4 V) were applied. The radiant temperature of the device surface was recorded using an infrared thermal imager. The figure shows that the device surface temperature gradually decreases as the forward voltage increases. This is because voltage-driven ion implantation into the MWCNT layer reduces its infrared emissivity, thereby reducing radiative heat dissipation and lowering the apparent temperature. When the voltage reaches +4 V, the device surface temperature can drop from the initial 36.2°C to 21.3°C, corresponding to an emissivity change Δε as high as 0.1-0.7. Gel-assembled devices with different ionomer contents (IL:TPU = 33%–90%) all exhibit similar modulation trends, and the modulation amplitude is positively correlated with the voltage magnitude.

[0054] Figure 6The response time curve of the all-solid-state flexible electro-induced infrared emissivity modulated device provided in Example 1 is shown. The test method involved using an infrared thermal imager to record the surface temperature change of the device over time under a step voltage (e.g., from 0 V to +3 V and back to 0 V). The response time was defined as the time required for the temperature to rise from the initial temperature change to 90% of the maximum temperature change. The figure shows the rapid decrease in surface temperature after the voltage is applied and the rapid recovery after the voltage is removed. The test results demonstrate that the device provided in this application has an extremely short dynamic response time of only 0.93 s (both rise and fall times are within 1 s), reflecting the rapid migration ability of ions in the solid gel and the highly efficient electrochemical doping characteristics of the MWCNT layer.

[0055] Figure 7 The image shows a pseudo-color image of the cooling process of the all-solid-state flexible electro-induced infrared emissivity modulated device provided in Example 1 under an infrared thermal imager. The image shows thermal imaging pseudo-color images at different time points (e.g., 0 s, 5 s, 15 s, 30 s) after applying different constant forward voltages (0V, +1V, +2V, +3V, +4V). Initially (0 s), the device surface exhibits a warm tone (red / yellow), indicating a high radiation temperature; as the voltage holding time increases, the color gradually transitions to a cool tone (blue / purple), visually reflecting the continuous decrease in the infrared radiation temperature of the device surface. This dynamic process is consistent with... Figure 6 The response time curves corroborate this, demonstrating the thermal image change characteristics of the device under actual working conditions. Under an infrared thermal imager, it exhibits a clearly discernible cooling pseudo-color change process, verifying its observable modulation effect in a real thermal imaging environment.

[0056] Figure 8 The diagram shows the cyclic stability test results of the all-solid-state flexible electro-induced infrared emissivity modulation device provided in Example 1. The test employed an automated programmable voltage source to perform long-term cyclic testing on the device: each cycle included applying a +3 V voltage and holding it for 30 s, then removing the voltage (0 V) and holding it for 30 s, with 2000 cycles. The infrared tuning range (i.e., emissivity tuned to amplitude Δε or temperature change ΔT) was recorded every 100 cycles. The horizontal axis represents the number of cycles, and the vertical axis represents the emissivity tuning to amplitude retention rate (%). The results show that after 2000 charge-discharge cycles, the infrared tuning performance retention rate of the device remains close to 86.6%, indicating that the device of this application possesses excellent cyclic stability and interface durability.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A fully solid-state flexible electro-induced infrared emissivity modulation device, characterized in that, In order, they include: Conductive layer; An ion gel electrolyte layer is hot-pressed and cured onto the conductive layer. Multi-walled carbon nanotube layers are hot-pressed and solidified onto the ion gel electrolyte layer; The ion gel electrolyte layer is composed of a polymer matrix and an ionic liquid. The ionic liquid contains imidazole cations and bis(trifluoromethanesulfonyl)imide anions. The multi-walled carbon nanotube layer has a three-dimensional porous network structure. The polymer matrix in the ion gel electrolyte layer permeates into the three-dimensional porous network structure.

2. The all-solid-state flexible electro-induced infrared emissivity modulation device as described in claim 1, characterized in that, In the ion gel electrolyte layer, the mass ratio of the ionic liquid to the polymer matrix is ​​33% to 90%.

3. The all-solid-state flexible electro-induced infrared emissivity modulation device as described in claim 1, characterized in that, The polymer matrix is ​​selected from one or more of thermoplastic polyurethane, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or polymethyl methacrylate.

4. The all-solid-state flexible electro-induced infrared emissivity modulation device as described in claim 1, characterized in that, The imidazole cation is selected from one or more of 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, or 1-propyl-3-methylimidazolium cation.

5. The all-solid-state flexible electro-induced infrared emissivity modulation device as described in claim 1, characterized in that, The conductive layer is a metal foil, a metal film, or a conductive carbon film.

6. The all-solid-state flexible electro-induced infrared emissivity modulation device as described in claim 1, characterized in that, The multi-walled carbon nanotube layer is a multi-walled carbon nanotube film, a single-walled carbon nanotube film, or a carbon nanotube array.

7. The all-solid-state flexible electro-induced infrared emissivity modulation device as described in claim 1, characterized in that, The all-solid-state flexible electro-infrared emissivity modulation device is a planar thin film.

8. A method for fabricating an all-solid-state flexible electro-induced infrared emissivity modulated device as described in any one of claims 1-7, characterized in that, include An ion gel electrolyte layer, a conductive layer, and a multi-walled carbon nanotube layer are provided. The ion gel electrolyte layer is composed of a polymer matrix and an ionic liquid, wherein the ionic liquid contains imidazole cations and bis(trifluoromethanesulfonyl)imide anions. The conductive layer, the ion gel electrolyte layer, and the multi-walled carbon nanotube layer are stacked sequentially and then subjected to hot-press curing treatment to allow the polymer matrix in the ion gel electrolyte layer to penetrate into the three-dimensional porous network structure of the multi-walled carbon nanotube layer.

9. The method as described in claim 8, characterized in that, In the ion gel electrolyte layer, the mass ratio of the ionic liquid to the polymer matrix is ​​between 33% and 90%.

10. The method as described in claim 8 or 9, characterized in that, The method further includes: The polymer matrix is ​​dissolved in an organic solvent and stirred at a first temperature to obtain a precursor solution; An ionic liquid is added to the precursor solution to form a mixed solution; The temperature of the mixed liquid is adjusted to a second temperature, stirring is continued, and ultrasonic oscillation treatment is applied to obtain a homogenized ion gel mixture. The polymer matrix is ​​selected from one or more of thermoplastic polyurethane, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or polymethyl methacrylate; the ionic liquid is selected from one or more of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, or 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide; and the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or tetrahydrofuran.

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