Flexible all-solid-state electrochromic device and preparation method thereof

Abstract

The invention provides a flexible all-solid-state electrochromic device and a preparation method thereof. The flexible all-solid-state electrochromic device comprises a main body structure, a matching structure and a flexible film, the main body structure comprises a UTG substrate, a first conductive layer, an electrochromic layer, an ion transmission layer, an ion storage layer and a second conductive layer which are sequentially arranged in a stacked mode, and the thickness of the UTG substrate is 200 micrometers or below. The matching structure comprises an electrode which is connected with the main body structure; the flexible film covers the surface of the main body structure and covers at least partial surface of the electrode. The UTG substrate not only can bear a high-temperature processing technology, but also can be bent, so that the main body structure of the device can be integrally annealed in a bent state, and the manufactured device has good flexibility and bending resistance; the external flexible film can reduce oxidation and water absorption of the device on the premise that the high-temperature processing resistance and the bending performance of the device are reserved, and the flexibility and the durability of the device are further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochromic devices, and particularly relates to a flexible all-solid-state electrochromic device and a preparation method thereof. Background Art

[0002] Electrochromism refers to the phenomenon that materials undergo reversible changes in optical properties (such as transmittance, reflectance, or color) under the action of an external electric field. Electrochromic devices can be classified into liquid electrolyte devices, gel-type devices, and all-solid-state devices according to the type of electrolyte. Compared with liquid electrolyte devices and gel-type devices, inorganic all-solid-state electrochromic devices have significant advantages such as higher stability, longer service life, and better environmental adaptability, and are thus widely used in fields such as smart windows, energy-saving buildings, and automotive sunroofs.

[0003] For example, with the development of new energy electric vehicle technology and the pursuit of green and environmentally friendly buildings, the demand for smart color-changing sunroofs has increased. Due to their unique structure, the requirements for electrochromic devices in such smart windows have shifted from planar to curved surfaces. However, currently industrialized electrochromic inorganic all-solid-state devices usually rely on complex processes such as sputtering and high-temperature heating, and are mainly based on traditional glass substrates. Due to the inherent rigidity of traditional glass, these devices are difficult to bend, which limits their applications. Therefore, developing electrochromic inorganic all-solid-state devices with certain flexibility and bending performance has become a key direction to solve this problem. Currently, traditional curved (flexible) electrochromic devices all have various limitations. Currently, the preparation of curved electrochromic devices mainly has two technical routes: indirect preparation on a flexible substrate and direct preparation on a curved substrate.

[0004] In the indirect preparation technology on a flexible substrate, traditional flexible substrates such as PET and CPI are usually used, and methods such as coating, sol-gel, and magnetron sputtering are used for preparation. There are mainly two deficiencies in such methods. One is that most flexible substrates are organic polymer structures with low strength, and irreversible deformation is likely to occur during processing and use, thereby damaging the structure of the electrochromic device. The other is that such materials have poor high-temperature and corrosion resistance, and it is difficult to adapt to diverse processing technologies (such as high-temperature sputtering, annealing, etc.), and the production methods are limited.

[0005] In the direct preparation technology of a curved surface substrate, a rigid non-planar substrate is directly used for preparation, such as curved glass. However, the preparation of curved glass itself requires special hot bending technology or superplastic forming technology, but these processes may affect the surface flatness and thickness uniformity of the glass, thus bringing difficulties to subsequent thin film deposition and device assembly. Moreover, during the hot bending process, residual stress may be formed inside the glass, increasing the risk of breakage during subsequent processing and device use. Currently, most thin film deposition technologies (such as sputtering, evaporation, or ALD) are more suitable for planar substrates. There are great challenges in preparing a uniform functional thin film on a curved substrate, which may lead to uneven film thickness and thus affect device performance. Inorganic materials (such as glass and thin films) themselves have high hardness and brittleness, which makes them prone to cracking or defects during the curved surface processing. This technology has limitations in both cost and mass production. When using an organic curved surface substrate for preparation, its material has poor high-temperature resistance and is difficult to adapt to diverse processing technologies (such as high-temperature sputtering, annealing, etc.).

[0006] Currently, the application of flexible inorganic all-solid-state electrochromic devices is limited by challenges in materials and processes, and the manufacturing difficulty is relatively high. However, with the progress of flexible material technology, deposition processes, and equipment, this field has broad development prospects. Especially in applications such as smart buildings, automobiles, and consumer electronics that require curved surface designs, technological breakthroughs will have important industrial value. Summary of the Invention

[0007] To solve all or part of the above technical problems, the present invention provides the following technical solutions:

[0008] One object of the present invention is to provide a flexible all-solid-state electrochromic device, and the flexible all-solid-state electrochromic device includes a main structure, a matching structure, and a flexible thin film;

[0009] The main structure includes a UTG substrate, a first conductive layer, an electrochromic layer, an ion transport layer, an ion storage layer, and a second conductive layer that are sequentially stacked, wherein the thickness of the UTG substrate is less than 200 μm;

[0010] The matching structure includes an electrode, and the electrode is connected to the main structure;

[0011] The flexible thin film covers the surface of the main structure and at least partially covers the surface of the electrode.

[0012] In some embodiments, the UTG substrate is an aluminosilicate glass substrate.

[0013] In some embodiments, the first conductive layer and the second conductive layer are independently an FTO conductive layer, an ITO conductive layer, an Ag / ITO / Ag composite conductive layer, or a metal nanowire conductive layer.

[0014] In some embodiments, the electrochromic layer is a WO3 layer, a TiO2 layer, or a MoO3 layer.

[0015] In some embodiments, the ion transport layer is a LiNbO3 ion transport layer or a LiTaO3 ion transport layer.

[0016] In some embodiments, the ion storage layer is a CeO2 ion storage layer or a NiO ion storage layer.

[0017] In some embodiments, the flexible film is a CPI film, a PET film, or a TPU film.

[0018] In some embodiments, the thickness of the UTG substrate is 30 - 200 um.

[0019] In some embodiments, the thicknesses of the first conductive layer and the second conductive layer are 100 - 400 nm.

[0020] In some embodiments, the thickness of the electrochromic layer is 100 - 400 nm.

[0021] In some embodiments, the thickness of the ion transport layer is 100 - 400 nm.

[0022] In some embodiments, the thickness of the ion storage layer is 100 - 200 nm.

[0023] In some embodiments, the thickness of the flexible film is 0.03 - 1 mm.

[0024] The second object of the present invention is to provide a method for preparing a flexible all - solid - state electrochromic device, and the preparation method includes:

[0025] Providing a UTG substrate, and sequentially forming a first conductive layer, an electrochromic layer, an ion transport layer, an ion storage layer, and a second conductive layer on the UTG substrate by physical vapor deposition to obtain a precursor structure;

[0026] Performing a first annealing treatment on the precursor structure to obtain a main structure;

[0027] Providing a matching structure on the main structure, and the matching structure includes an electrode;

[0028] Coating a flexible film on the surface of the main structure and at least a part of the surface of the electrode to obtain a flexible all - solid - state electrochromic device.

[0029] The UTG substrate described in the present invention refers to an ultra-thin glass substrate with a thickness of less than 200 μm. The flexible all-solid-state electrochromic device prepared based on the UTG substrate has bendable performance. However, the present invention discovers that internal stress will be generated in the materials of the flexible electrochromic device prepared with ultra-thin glass (UTG substrate) after bending, which affects the number of bending times, bending curvature, electrochromic cycling performance, and electrochromic response time of the device. The present invention discovers that performing an overall first annealing treatment on the precursor structure can reduce the internal stress of the device and improve the flexibility of the device.

[0030] The heat-resistant temperature of the UTG substrate (ultra-thin glass substrate) is relatively high (for example, the heat-resistant temperature of the UTG substrate made of aluminosilicate glass is not lower than 550 °C). It can not only withstand high-temperature processing technology but also can be bent. Due to the good heat resistance of the UTG substrate, the preparation method provided by the present invention can perform the first annealing on the precursor structure to reduce the internal stress of the device and improve the flexibility of the device. Moreover, the high hardness of the UTG substrate can provide good support for the device and reduce the possibility of film layer fracture. The flexible all-solid-state electrochromic device provided by the present invention is mainly composed of inorganic solid components, ensuring its safety in applications such as green buildings and new energy vehicles.

[0031] In some embodiments, the first annealing treatment is performed in the bent state or non-bent state of the precursor structure. Based on the good bendability of the UTG substrate, the overall annealing of the device precursor structure can be carried out in the bent state, enhancing the usability of the device and realizing the planar processing and curved surface application of the device.

[0032] In some embodiments, the first annealing treatment specifically includes: heating to 100 - 500 °C at a heating rate of 2 - 10 °C / min in an inert atmosphere or an atmosphere containing a reducing gas and holding for 0.5 - 2 h.

[0033] Further, the inert atmosphere includes argon.

[0034] Further, the atmosphere containing a reducing gas includes an inert gas and hydrogen. The flow ratio of the inert gas to hydrogen can be 200:10 - 200:40.

[0035] In some embodiments, the physical vapor deposition method includes one or a combination of magnetron sputtering, thermal evaporation, electron beam evaporation, atomic layer deposition, etc.

[0036] In some embodiments, the physical vapor deposition method preferably includes magnetron sputtering.

[0037] Further, the process conditions for depositing the first conductive layer and the second conductive layer by magnetron sputtering include: at a vacuum degree of 6×10 -3Below Pa, the sputtering mode is radio frequency mode, the atmosphere is argon and the flow rate is 50 - 100 sccm, the sputtering pressure is 0.5 - 1.5 Pa, the power is 50 - 200 W, and the deposition time is 600 - 4800 s.

[0038] Further, the process conditions for depositing the electrochromic layer by magnetron sputtering include: the vacuum degree is below 6×10 -3 Pa, set the sputtering mode to DC sputtering, the atmosphere is a mixed atmosphere containing oxygen and argon, where the oxygen flow rate is 25 - 50 sccm, the argon flow rate is 80 - 200 ccm, the sputtering pressure is 0.5 - 1.5 Pa, the power is 50 - 200 W, and the deposition time is 600 - 1800 s.

[0039] Further, the process conditions for depositing the ion transport layer and the ion storage layer by magnetron sputtering include: the vacuum degree is below 6×10 -3 Pa, the sputtering mode is radio frequency mode, the atmosphere is a mixed atmosphere containing oxygen and argon, where the oxygen flow rate is 1 - 10 sccm, the argon flow rate is 80 - 200 ccm, the sputtering pressure is 0.5 - 1.5 Pa, the power is 50 - 200 W, and the deposition time is 6000 - 18000 s.

[0040] In some embodiments, after depositing the first conductive layer on the UTG substrate by magnetron sputtering, it further includes a step of performing a second annealing on the UTG substrate containing the first conductive layer. The second annealing specifically includes: in an inert atmosphere or an atmosphere containing a reducing gas, heating the temperature to 350 - 550 °C at a heating rate of 2 - 10 °C / min and holding for 0.5 - 2 h. The second annealing can reduce the internal stress of the material and improve the modulation amplitude and response time of the device.

[0041] Further, the inert atmosphere includes argon.

[0042] Further, the atmosphere containing a reducing gas includes an inert gas and hydrogen, and the flow rate ratio of the inert gas to hydrogen is 200:10 - 200:40.

[0043] In some embodiments, the material of the UTG substrate includes aluminosilicate glass.

[0044] In some embodiments, the materials of the first conductive layer and the second conductive layer include one or a combination of FTO, ITO, and conductive metals.

[0045] In some embodiments, the material of the electrochromic layer includes one or a combination of WO3, TiO2, and MoO3.

[0046] In some embodiments, the material of the ion transport layer includes LiNbO3 and / or LiTaO3.

[0047] In some embodiments, the material of the ion storage layer includes CeO2 and / or NiO;

[0048] In some embodiments, the material of the flexible film includes one or a combination of CPI, PET, and TPU.

[0049] In some embodiments, the thickness of the UTG substrate is less than 200 um, preferably 30 - 200 um.

[0050] In some embodiments, the thicknesses of the first conductive layer and the second conductive layer are 100 - 400 nm.

[0051] In some embodiments, the thickness of the electrochromic layer is 100 - 400 nm.

[0052] In some embodiments, the thickness of the ion transport layer is 100 - 400 nm.

[0053] In some embodiments, the thickness of the ion storage layer is 100 - 200 nm.

[0054] In some embodiments, the thickness of the flexible film is 0.03 - 1 mm.

[0055] Compared with the prior art, the present invention has at least the following technical effects:

[0056] (1) The flexible all - solid - state electrochromic device provided by the present invention has good flexibility and bending resistance, and can be bent to the required curvature during use. Specifically, it uses an ultra - thin glass as the substrate, and the heat - resistant temperature of the UTG substrate is not lower than 550 °C. It can not only match high - temperature processing processes, but also enable bending, and the device can be annealed as a whole in the bent state, enhancing the usability of the device and realizing planar processing and curved - surface application of the device.

[0057] (2) By setting the flexible film, the present invention reduces the oxidation and water absorption of the device while retaining the high - temperature processing ability and bending performance of the device, and further improves the flexibility and durability of the device.

[0058] (3) After obtaining the precursor structure, the preparation method of the flexible all - solid - state electrochromic device provided by the present invention performs a first annealing treatment to reduce the internal stress of the device, and covers it with a flexible film to further improve the flexibility and durability of the device while retaining the bending performance of the device. Description of the Drawings

[0059] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0060] Figure 1 is a schematic structural diagram of the flexible all-solid-state electrochromic device of Example 1;

[0061] Figure 2 is a SEM structural diagram of a partial main structure of the flexible all-solid-state electrochromic device of Example 1;

[0062] Figure 3 is a physical diagram of the colored state of the flexible all-solid-state electrochromic device of Example 1;

[0063] Figure 4 is a physical diagram of the bleached state of the flexible all-solid-state electrochromic device of Example 1;

[0064] Figure 5 is a modulation spectrogram of the colored state and the bleached state of the flexible all-solid-state electrochromic device of Example 1;

[0065] 1 - UTG ultra-thin aluminosilicate glass, 2 - first ITO conductive layer, 3 - WO3 layer, 4 - LiNbO3 layer, 5 - CeO2 layer, 6 - second ITO conductive layer, 7 - CPI film, 8 - electrode. Detailed Embodiments

[0066] The following will specifically describe the technical solutions of the present invention in detail in combination with specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as restrictive, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in any appropriate detailed embodiment in different ways.

[0067] In addition, unless otherwise specified, various raw materials used in the following embodiments can be obtained from the market or other channels, and various production and testing equipment used are also known equipment in the art, and the testing methods used are also conventional methods in the art.

[0068] Example 1

[0069] This embodiment provides a flexible all-solid-state electrochromic device and a preparation method thereof. Figure 1 is a schematic structural diagram of the flexible all-solid-state electrochromic device of this embodiment, as Figure 1As shown, the flexible all-solid-state electrochromic device includes a main structure, a matching structure, and a flexible film 7; the main structure includes a UTG ultra-thin aluminum-silicon glass substrate 1, a first ITO conductive layer 2, a WO3 layer 3, a LiNbO3 layer 4, a CeO2 layer 5, and a second ITO conductive layer 6 that are sequentially stacked; the matching structure includes a copper electrode 8, and the copper electrode 8 is in contact connection with the main structure; the flexible film 7 is a CPI film, and the CPI film covers the surfaces of the main structure and the electrode.

[0070] Among them, the thickness of the UTG ultra-thin aluminum-silicon glass substrate 1 is 30 μm, the thickness of the first ITO conductive layer 2 is 200 nm, the thickness of the WO3 layer 3 is 320 nm, the thickness of the LiNbO3 layer 4 is 270 nm, the thickness of the CeO2 layer 5 is 160 nm, and the thickness of the second ITO conductive layer 6 is 200 nm; the thickness of the CPI film 7 is 0.03 mm, and the CPI film can reduce the oxidation and water absorption of the device and enhance the toughness of the device.

[0071] The preparation method of the flexible all-solid-state electrochromic device specifically includes the following steps:

[0072] (1) Ultrasonically clean the UTG ultra-thin aluminum-silicon glass (with a thickness of 30 μm and a size of 20 mm × 30 mm × 0.03 mm) in ethanol for 10 min, and dry it through a vacuum oven.

[0073] (2) Transfer the cleaned and dried UTG ultra-thin aluminum-silicon glass to the vacuum chamber of a magnetron sputtering system, pump the air pressure to 6×10 -3 Pa, use an ITO target to sputter an ITO conductive layer with a thickness of 200 nm, the sputtering mode is radio frequency mode, the deposition parameters are argon 60 sccm, the sputtering air pressure is 0.8 Pa, the power is 100 W, and the deposition time is 1200 s to obtain a UTG / ITO composite structure.

[0074] (3) Place the UTG / ITO composite structure in a tube furnace, in an argon atmosphere (argon flow rate 1200 sccm), heat it to 400 °C at a heating rate of 5 °C / min and anneal for 0.5 h, and naturally cool to room temperature after the annealing ends.

[0075] (4) Transfer the UTG / ITO composite structure annealed in step (3) to the magnetron sputtering vacuum chamber. After the air pressure is pumped to 6×10 -3 Pa, use a W target to sputter a WO3 thin film. The sputtering mode is DC sputtering. The specific deposition parameters are O2:Ar = 27 sccm:81 sccm, the sputtering air pressure is 1.2 Pa, the power is 100 W, and the deposition time is 1200 s to obtain a UTG / ITO / WO3 composite structure.

[0076] (5) Then, a magnetron sputtering device is used to deposit an ion transport layer on the UTG / ITO / WO3 composite structure. The vacuum degree is pumped to 4×10 -4 Pa. The radio frequency mode and a LiNbO3 target are selected. The power is set to 100 W, the gas pressure is 1.1 Pa, the gas flow ratio of oxygen to argon is set to 5 sccm:95 sccm, and the deposition time is 12000 s, obtaining a UTG / ITO / WO3 / LiNbO3 composite structure.

[0077] (6) Next, a magnetron sputtering device is used to deposit an ion storage layer on the LiNbO3 layer of the UTG / ITO / WO3 / LiNbO3 composite structure. The vacuum degree is pumped to 4×10 -4 Pa. The radio frequency mode and a CeO2 target are selected. The power is 100 W, the gas pressure is 1.1 Pa, the gas flow ratio of oxygen to argon is set to 5 sccm:95 sccm, and the deposition time is 6000 s, obtaining a UTG / ITO / WO3 / LiNbO3 / CeO2 composite structure.

[0078] (7) Finally, a magnetron sputtering device is used to deposit a bottom ITO conductive layer. The vacuum degree is pumped to 4×10 -4 Pa. The radio frequency mode and an ITO target are selected. The power is 100 W, the gas pressure is 0.8 Pa, the argon flow rate is 60 sccm, and the deposition time is 1200 s, obtaining a UTG / ITO / WO3 / LiNbO3 / CeO2 / ITO structure, denoted as the precursor structure;

[0079] (8) The precursor structure obtained in step (7) is annealed in a tube furnace. The atmosphere is an argon atmosphere and the argon flow rate is 1200 sccm. It is heated to 150 °C at a heating rate of 5 °C / min and held for 0.5 h to obtain the main structure.

[0080] (9) After the annealing is completed, it is naturally cooled to room temperature, and then copper electrodes are assembled. A CPI film with a thickness of 0.03 mm is coated on the surfaces of the main structure and the copper electrodes, obtaining a flexible all-solid-state electrochromic device.

[0081] Figure 2 is a partial SEM structure diagram of the flexible all-solid-state electrochromic device of this embodiment, Figure 3 is a physical diagram of the colored state of the flexible all-solid-state electrochromic device of this embodiment, Figure 4 is a physical diagram of the bleached state of the flexible all-solid-state electrochromic device of this embodiment, Figure 5 is the modulation spectrum diagram of the colored state and the bleached state of the flexible all-solid-state electrochromic device of this embodiment.

[0082] The flexibility of the device prepared in Example 1 was tested. When the bending radius of the device was 1 cm and it was bent 500 times, the modulation amplitude of the device did not show a decay of more than 10%.

[0083] The durability of the device prepared in Example 1 was tested, and it was found that after 1000 cycles (±3V voltage), the device still had a modulation amplitude of 40% at 630 nm.

[0084] The maximum temperature tolerance of the UTG ultra-thin aluminum-silicon glass substrate in Example 1 was 550 °C. Compared with ordinary flexible substrates (generally with a temperature resistance of no more than 200 °C), it can withstand high-temperature processing processes.

[0085] Bending to the required curvature: The device prepared in this example can be applied to the sunroof of new energy vehicles, and the ideal bending radius of the device is 1 mm.

[0086] The coloring time of the device in Example 1 was 15 s and the fading time was 25 s.

[0087] Example 2

[0088] Example 2 was basically the same as Example 1, except that in the preparation method of Example 2, step (3) included:

[0089] The UTG / ITO composite structure was placed in a tube furnace and heated to 400 °C at a heating rate of 5 °C / min in an argon atmosphere (argon flow rate 1200 sccm) and held for 1 h, and then naturally cooled to room temperature after the annealing was completed.

[0090] The rest was implemented in the same way as in Example 1 and will not be elaborated here.

[0091] Example 3

[0092] Example 3 was basically the same as Example 1, except that in the preparation method of Example 3, step (3) included:

[0093] The UTG / ITO composite structure was placed in a tube furnace and heated to 450 °C at a heating rate of 5 °C / min in an argon atmosphere (argon flow rate 1200 sccm) and held for 0.5 h, and then naturally cooled to room temperature after the annealing was completed.

[0094] The rest was implemented in the same way as in Example 1 and will not be elaborated here.

[0095] The performance of the device prepared in Example 3 was comparable to that of Example 1.

[0096] Example 4

[0097] Example 4 was basically the same as Example 1, except that step (8) of Example 4 included:

[0098] Anneal the precursor structure obtained in step (7) in a tube furnace under an argon atmosphere with a flow rate of 1200 sccm. Heat it at a heating rate of 10 °C / min to 100 °C and hold for 1 h to obtain the main structure. The other examples are the same as those in Example 1 and will not be elaborated here.

[0099] The performance of the device obtained in Example 4 is comparable to that of Example 1.

[0100] Example 5

[0101] Example 5 is basically the same as Example 1, except that step (8) of Example 5 includes:

[0102] Anneal the precursor structure obtained in step (7) in a tube furnace under an argon atmosphere with a flow rate of 1200 sccm. Heat it at a heating rate of 2 °C / min to 500 °C and hold for 2 h to obtain the main structure. The other examples are the same as those in Example 1 and will not be elaborated here.

[0103] The performance of the device obtained in Example 5 is comparable to that of Example 1.

[0104] Example 6

[0105] Example 6 provides a preparation method for a flexible all-solid-state electrochromic device, which specifically includes the following steps:

[0106] (1) Ultrasonic clean the UTG ultra-thin aluminum-silicon glass (thickness 30 μm, size 20 mm × 30 mm × 0.03 mm) in ethanol for 10 min and dry it through a vacuum oven.

[0107] (2) Transfer the cleaned and dried UTG ultra-thin aluminum-silicon glass to the vacuum chamber of a magnetron sputtering system, pump the air pressure to 6×10 -3 Pa, use an ITO target to sputter an ITO conductive layer with a thickness of 110 nm. The sputtering mode is the radio frequency mode, and the deposition parameters are argon 50 sccm, sputtering air pressure 0.5 Pa, power 50 W, and deposition time 600 s to obtain the UTG / ITO composite structure.

[0108] (3) Place the UTG / ITO composite structure in a tube furnace, and under an argon atmosphere (argon flow rate 1200 sccm), heat it at a heating rate of 5 °C / min to 400 °C for annealing for 0.5 h. After annealing, cool it naturally to room temperature.

[0109] (4) Transfer the UTG / ITO composite structure annealed in step (3) to the magnetron sputtering vacuum chamber. Wait until the air pressure is pumped to 6×10 -3After reaching 0.5 Pa, a W target was used to sputter the WO3 thin film. The sputtering mode was DC sputtering. The specific deposition parameters were: O2:Ar = 25 sccm:80 sccm, the sputtering gas pressure was 0.5 Pa, the power was 50 W, and the deposition time was 600 s, obtaining a UTG / ITO / WO3 composite structure.

[0110] (5) Then, a magnetron sputtering device was used to deposit an ion transport layer on the UTG / ITO / WO3 composite structure. The vacuum was pumped to 6×10 -3 Pa. The RF mode and a LiNbO3 target were selected. The power was set to 50 W, the gas pressure was 0.5 Pa, the oxygen flow rate was set to 1 sccm, the argon flow rate was 80 sccm, and the deposition time was 6000 s, obtaining a UTG / ITO / WO3 / LiNbO3 composite structure.

[0111] (6) Then, a magnetron sputtering device was used to deposit an ion storage layer on the LiNbO3 layer of the UTG / ITO / WO3 / LiNbO3 composite structure. The vacuum was pumped to 6×10 -3 Pa. The RF mode and a CeO2 target were selected. The power was 50 W, the gas pressure was 0.5 Pa, the oxygen flow rate was set to 1 sccm, the argon flow rate was 80 sccm, and the deposition time was 8000 s, obtaining a UTG / ITO / WO3 / LiNbO3 / CeO2 composite structure.

[0112] (7) Finally, a magnetron sputtering device was used to deposit a bottom ITO conductive layer. The vacuum was pumped to 6×10 -3 Pa. The RF mode and an ITO target were selected. The power was 50 W, the gas pressure was 0.5 Pa, the argon flow rate was 50 sccm, and the deposition time was 600 s, obtaining a UTG / ITO / WO3 / LiNbO3 / CeO2 / ITO structure, denoted as the precursor structure.

[0113] (8) The precursor structure obtained in step (7) was annealed in a tube furnace. The atmosphere was an argon atmosphere with an argon flow rate of 1200 sccm. It was heated to 150 °C at a heating rate of 5 °C / min and held for 0.5 h to obtain the main structure.

[0114] (9) After the annealing was completed, it was naturally cooled to room temperature. Then, copper electrodes were assembled, and a CPI film with a thickness of 0.03 mm was coated on the surfaces of the main structure and the copper electrodes, obtaining a flexible all-solid-state electrochromic device.

[0115] Example 7

[0116] Example 7 provides a method for preparing a flexible all-solid-state electrochromic device, which specifically includes the following steps:

[0117] (1) Ultrasonically clean the UTG ultra-thin aluminum-silicon glass (thickness 30 μm, size 20 mm × 30 mm × 0.03 mm) in ethanol for 10 min, and dry it in a vacuum oven.

[0118] (2) Transfer the cleaned and dried UTG ultra-thin aluminum-silicon glass to the vacuum chamber of a magnetron sputtering system, pump the air pressure down to 6×10 -3 Pa, use an ITO target to sputter a 400-nm-thick ITO conductive layer. The sputtering mode is the radio frequency mode, and the deposition parameters are 100 sccm of argon, a sputtering air pressure of 1.5 Pa, a power of 200 W, and a deposition time of 4800 s to obtain a UTG / ITO composite structure.

[0119] (3) Place the UTG / ITO composite structure in a tube furnace, and in an argon atmosphere (argon flow rate 1200 sccm), heat it to 400 °C at a heating rate of 5 °C / min and anneal for 0.5 h. After the annealing is completed, let it cool naturally to room temperature.

[0120] (4) Transfer the UTG / ITO composite structure annealed in step (3) to the magnetron sputtering vacuum chamber. After pumping the air pressure down to 6×10 -3 Pa, use a W target to sputter a WO3 thin film. The sputtering mode is direct current sputtering. The specific deposition parameters are 50 sccm of O2: 200 sccm of Ar, a sputtering air pressure of 1.5 Pa, a power of 200 W, and a deposition time of 1800 s to obtain a UTG / ITO / WO3 composite structure.

[0121] (5) Then use a magnetron sputtering device to deposit an ion transport layer on the UTG / ITO / WO3 composite structure. Pump the vacuum degree down to 4×10 -4 Pa, select the radio frequency mode and a LiNbO3 target, set the power to 200 w, the air pressure to 1.5 Pa, set the oxygen flow rate to 10 sccm, the argon flow rate to 200 sccm, and the deposition time to 18000 s to obtain a UTG / ITO / WO3 / LiNbO3 composite structure.

[0122] (6) Then use a magnetron sputtering device to deposit an ion storage layer on the LiNbO3 layer of the UTG / ITO / WO3 / LiNbO3 composite structure. Pump the vacuum degree down to 4×10 -4 Pa, select the radio frequency mode and a CeO2 target, the power is 200 W, the air pressure is 1.5 Pa, set the oxygen flow rate to 10 sccm, the argon flow rate to 200 sccm, and the deposition time to 10000 s to obtain a UTG / ITO / WO3 / LiNbO3 / CeO2 composite structure.

[0123] (7) Finally, use a magnetron sputtering device to deposit a bottom ITO conductive layer. Pump the vacuum degree down to 4×10 -4Pa, select the radio frequency mode and ITO target, with a power of 200 W, a pressure of 1.5 Pa, an argon flow rate of 100 sccm, and a deposition time of 4800 s to obtain the UTG / ITO / WO3 / LiNbO3 / CeO2 / ITO structure, denoted as the precursor structure.

[0124] (8) Anneal the precursor structure obtained in step (7) in a tube furnace. The atmosphere is an argon atmosphere with an argon flow rate of 1200 sccm. Heat it at a heating rate of 5 °C / min to 150 °C and hold for 0.5 h to obtain the main structure.

[0125] (9) After the annealing is completed, cool it naturally to room temperature, then assemble the copper electrodes, and coat a CPI film with a thickness of 0.03 mm on the surfaces of the main structure and the copper electrodes to obtain the flexible all-solid-state electrochromic device.

[0126] Example 8

[0127] Example 8 provides a flexible all-solid-state electrochromic device, which includes a main structure, a matching structure, and a flexible film; the main structure includes a UTG ultra-thin aluminum-silicon glass substrate, a first FTO conductive layer, a TiO2 layer, a LiTaO3 layer, a NiO layer, and a second FTO conductive layer that are sequentially stacked; the matching structure includes copper electrodes, and the copper electrodes are in contact connection with the main structure; the flexible film is a PET film, and the PET film covers the surface of the main structure;

[0128] Among them, the thickness of the UTG ultra-thin aluminum-silicon glass substrate is 30 μm, the thickness of the first FTO conductive layer is 100 nm, the thickness of the TiO2 layer is 100 nm, the thickness of the LiTaO3 layer is 100 nm, the thickness of the NiO layer is 100 nm, and the thickness of the second FTO conductive layer is 100 nm. The thickness of the PET film is 0.1 mm, and the PET film can reduce the oxidation and water absorption of the device and enhance the toughness of the device.

[0129] Example 9

[0130] Example 9 provides a flexible all-solid-state electrochromic device, which includes a main structure, a matching structure, and a flexible film; the main structure includes a UTG ultra-thin aluminum-silicon glass substrate, a first ITO conductive layer, a MoO3 layer, a LiTaO3 layer, a CeO2 layer, and a second ITO conductive layer that are sequentially stacked; the matching structure includes copper electrodes, and the copper electrodes are in contact connection with the main structure; the flexible film is a TPU film, and the TPU film covers the surface of the main structure;

[0131] Among them, the thickness of the UTG ultra-thin aluminum-silicon glass substrate is 200 μm, the thickness of the first ITO conductive layer is 400 nm, the thickness of the WO3 layer is 400 nm, the thickness of the LiTaO3 layer is 400 nm, the thickness of the CeO2 layer is 200 nm, and the thickness of the second ITO conductive layer is 400 nm. The thickness of the TPU film is 1 mm, and the TPU film can reduce the oxidation and water absorption of the device and enhance the toughness of the device.

[0132] Comparative Example 1

[0133] The difference between Comparative Example 1 and Example 1 is only that Comparative Example 1 does not perform the annealing step in step (3). The rest is the same as that of Example 1 and will not be elaborated here.

[0134] Comparing Examples 1-3 and Comparative Example 1, it is found that the resistance of the UTG / ITO composite structure after being treated by the annealing step in step (3) in Examples 1-3 is lower; compared with Comparative Example 1, the resistance of the conductive layer in Example 1 is reduced by about 60%. Moreover, the cycle stability (life) of the device prepared in Example 1 is improved by about 50%, and the discoloration response speed is improved by about 15%.

[0135] Comparative Example 2

[0136] The difference between Comparative Example 2 and Example 1 is only that Comparative Example 2 does not perform the annealing step in step (8). The rest is the same as that of Example 1 and will not be elaborated here.

[0137] Comparing Examples 1, 4, 5 and Comparative Example 2, it is found that after the precursor structure is prepared, annealing in step (8) can reduce the internal stress of the main structure and improve the flexibility and durability of the device. Compared with Comparative Example 2, the anti-lateral shear ability of the device in Example 1 is improved by 50%; when the bending radius is 1 cm and bent 100 times, the device in Example 1 does not show a performance decay of more than 5%. Moreover, compared with Comparative Example 2, the discoloration response speed of the device in Example 1 is improved by about 15%.

[0138] Comparative Example 3

[0139] The difference between Comparative Example 3 and Example 1 is only that the flexible all-solid-state electrochromic device in Comparative Example 3 does not have a CPI film.

[0140] Comparing Example 1 and Comparative Example 3, it is found that compared with the device without the CPI film, the anti-shearing ability of the device with the CPI film is improved by about 50%, indicating that the film coating can improve the flexibility and durability of the device.

[0141] The present invention also tests the diagonal line resistance and the transmittance of the 630 nm colored state / faded state of the devices in Examples 1-2 and Comparative Examples 1-2 above. The test results are shown in Table 1.

[0142] Table 1

[0143] Group Diagonal line resistance / Ohm 630nm transmittance in the faded state 630nm transmittance in the colored state Example 1 75 8％ 70％ Example 2 75 8％ 70％ Comparative Example 1 210 8％ 70％ Comparative Example 2 75 10％ 65％

[0144] In Table 1, the diagonal line resistance was measured using a multimeter for a 3*4 cm sample, and the average value was taken after three tests.

[0145] All aspects, embodiments, features, and examples of the present invention should be considered illustrative in all respects and are not intended to limit the present invention. The scope of the present invention is defined only by the claims. Without departing from the spirit and scope of the claimed invention, those skilled in the art will appreciate other embodiments, modifications, and uses.

[0146] In addition, the inventors of this case also referred to the foregoing embodiments and conducted tests using other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0147] Although the present invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made and elements of the embodiments can be replaced with substantially equivalent elements without departing from the spirit and scope of the present invention. Additionally, many modifications can be made to adapt a particular situation or material to the teachings of the present invention without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the specific embodiments disclosed for carrying out the present invention, but is intended to include all embodiments that fall within the scope of the appended claims. Moreover, unless specifically stated, any use of the terms first, second, etc. does not denote any order or importance, but the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A flexible all-solid-state electrochromic device, characterized in that: It includes a main structure, a matching structure and a flexible film; The main structure comprises a UTG substrate, a first conductive layer, an electrochromic layer, an ion transport layer, an ion storage layer and a second conductive layer stacked in sequence, wherein the thickness of the UTG substrate is less than 200 μm; The matching structure includes an electrode, and the electrode is connected to the main structure; The flexible film is coated on the surface of the main structure and at least a part of the surface of the electrode.

2. The flexible all-solid-state electrochromic device according to claim 1, characterized in that: The UTG substrate is an aluminosilicate glass substrate; And / or, the first conductive layer and the second conductive layer are independently a FTO conductive layer, an ITO conductive layer, an Ag / ITO / Ag composite conductive layer or a metal nanowire conductive layer; And / or, the electrochromic layer is a WO3 layer, a TiO2 layer or a MoO3 layer; And / or, the ion transport layer is a LiNbO3 layer or a LiTaO3 layer; And / or, the ion storage layer is a CeO2 layer or a NiO layer; And / or, the flexible film is a CPI film, a PET film or a TPU film.

3. The flexible all-solid-state electrochromic device according to claim 1, characterized in that: The thickness of the UTG substrate is 30-200 μm; And / or, the thickness of the first conductive layer and the second conductive layer is 100-400 nm; And / or, the thickness of the electrochromic layer is 100-400 nm; And / or, the thickness of the ion transport layer is 100-400 nm; And / or, the thickness of the ion storage layer is 100-200 nm; And / or, the thickness of the flexible film is 0.03-1 mm.

4. A method for preparing a flexible all-solid-state electrochromic device, characterized in that: include: Providing a UTG substrate, and sequentially forming a first conductive layer, an electrochromic layer, an ion transport layer, an ion storage layer, and a second conductive layer on the UTG substrate by a physical vapor deposition method to obtain a precursor structure; Performing a first annealing treatment on the precursor structure to obtain a main structure; A matching structure is provided on the main structure, wherein the matching structure includes an electrode; A flexible film is coated on the surface of the main structure and at least a part of the surface of the electrode to obtain a flexible all-solid-state electrochromic device.

5. The preparation method according to claim 4, characterized in that: The physical vapor deposition method includes one or a combination of magnetron sputtering, thermal evaporation, electron beam evaporation, and atomic layer deposition, and preferably includes magnetron sputtering.

6. The preparation method according to claim 4, characterized in that: The first annealing treatment specifically includes: in an inert atmosphere or an atmosphere containing a reducing gas, heating to 100-500° C. at a heating rate of 2-10° C. / min and keeping the temperature for 0.5-2 hours; Preferably, the inert atmosphere comprises argon; Preferably, the atmosphere containing reducing gas includes inert gas and hydrogen.

7. The preparation method according to claim 5, characterized in that: The process conditions for depositing the first conductive layer and the second conductive layer by magnetron sputtering include: vacuum degree of 6×10 -3 Pa or less, the sputtering mode is RF mode, the atmosphere is argon with a flow rate of 50-100 sccm, the sputtering pressure is 0.5-1.5 Pa, the power is 50-200 W, and the deposition time is 600-4800 s; And / or, the process conditions for depositing the electrochromic layer by magnetron sputtering include: vacuum degree of 6×10 -3 Pa or less, the sputtering mode is DC sputtering, the atmosphere is a mixed atmosphere containing oxygen and argon, wherein the oxygen flow rate is 25-50sccm, the argon flow rate is 80-200ccm, the sputtering pressure is 0.5-1.5Pa, the power is 50-200W, and the deposition time is 600-1800s; And / or, the process conditions for depositing the ion transport layer and the ion storage layer by magnetron sputtering include: a vacuum degree of 6×10 -3 Pa, the sputtering mode is the RF mode, the atmosphere is a mixed atmosphere containing oxygen and argon, wherein the oxygen flow rate is 1-10sccm, the argon flow rate is 80-200ccm, the sputtering pressure is 0.5-1.5Pa, the power is 50-200W, and the deposition time is 6000-18000s.

8. The preparation method according to claim 7, characterized in that: After depositing the first conductive layer on the UTG substrate by magnetron sputtering, the method further includes performing a second annealing on the UTG substrate containing the first conductive layer, wherein the second annealing specifically includes: in an inert atmosphere or an atmosphere containing a reducing gas, heating the temperature to 350-550° C. at a heating rate of 2-10° C. / min and keeping the temperature for 0.5-2 hours; Preferably, the inert atmosphere comprises argon; Preferably, the atmosphere containing reducing gas includes inert gas and hydrogen, and the flow ratio of the inert gas to hydrogen is 200:10-200:

40.

9. The preparation method according to claim 4, characterized in that: The material of the UTG substrate includes aluminosilicate glass; And / or, the material of the first conductive layer and the second conductive layer includes one or a combination of FTO, ITO, and conductive metal; And / or, the material of the electrochromic layer includes one or a combination of WO3, TiO2, and MoO3; And / or, the material of the ion transport layer includes LiNbO3 and / or LiTaO3; And / or, the material of the ion storage layer includes CeO2 and / or NiO; And / or, the material of the flexible film includes one or a combination of CPI, PET, and TPU.

10. The preparation method according to claim 4, characterized in that: The thickness of the UTG substrate is less than 200 μm, preferably 30-200 μm; And / or, the thickness of the first conductive layer and the second conductive layer is 100-400 nm; And / or, the thickness of the electrochromic layer is 100-400 nm; And / or, the thickness of the ion transport layer is 100-400 nm; And / or, the thickness of the ion storage layer is 100-200 nm; And / or, the thickness of the flexible film is 0.03-1 mm.

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