Electrochromic sheet and method for manufacturing the same

Abstract

The present application belongs to the field of electrochromic, and particularly relates to an electrochromic sheet and a preparation method thereof. The electrochromic sheet comprises, from bottom to top, a first transparent substrate layer, a first transparent conductive layer, an electrochromic layer, an ion conduction layer, a first ion storage layer and a second transparent conductive layer, wherein the first transparent conductive layer and the second transparent conductive layer have metal grids. The ion conduction layer is a solid-state electrolyte layer formed by vacuum magnetron sputtering of a lithium-zinc oxide target and a silicon target. The electrochromic sheet has excellent color changing speed and cycle stability, and slow electrical performance attenuation, and has good application value in the development and research of smart wearable devices and AR glasses.

Description

Technical Field

[0001] This invention belongs to the field of electrochromism, specifically, it relates to an electrochromic sheet and its preparation method. Background Technology

[0002] Electrochromism refers to the phenomenon where optical properties (reflectivity, transmittance, absorptivity, etc.) undergo stable and reversible color changes under the influence of an applied electric field. Electrochromic technology has been developing for over forty years. Electrochromic devices (ECDs) have broad application prospects in fields such as smart windows, displays, spacecraft temperature control modulation, glare-free automotive rearview mirrors, and weapon stealth due to their characteristics such as continuous adjustability of transmitted light intensity, low energy loss, and open-circuit memory function. ECD-based glass, as a new type of smart window, can adjust the intensity of incident sunlight according to comfort needs, effectively reducing energy consumption and demonstrating significant energy-saving effects. Among them, digitally controlled electrochromic lenses can adjust the intensity and energy of incident sunlight according to comfort needs, effectively reducing the transmittance of ambient light, and can be widely used in smart wearable devices, such as photochromic sunglasses, AR / VR / MR, and transparent display back panels.

[0003] With the continuous advancement of technology, people have gradually developed a demand for wearable smart electronic products. Wearable products require materials with certain mechanical strength, capable of being stretched, twisted, folded, and wrinkled without performance degradation. These products can adapt to complex non-planar surfaces and have application areas that rigid devices cannot. Among them, electrochromic materials have high application value because they can achieve color changes under low voltage control.

[0004] For example, CN104714348A discloses a wearable smart color-changing device. This device is based on a stretchable substrate, onto which a carbon conductive layer and a PANI electrochromic layer are sequentially deposited. By selecting the appropriate fabrication method and controlling the fabrication conditions, it achieves a balance of electrochromic performance, energy storage capacity, and wearable functionality. The smart color-changing device senses changes in energy storage through PANI and expresses these changes in color. This color-changing device is safe, effective, energy-efficient, and environmentally friendly, and can be widely used in various fields.

[0005] CN104932169A discloses a fast-response flexible electrochromic device and its application as a wearable electronic product in the field of smart electronic products. The flexible electrochromic device includes: a working electrode, a counter electrode, and an electrolyte layer, wherein the working electrode is a transparent fast-response flexible electrochromic film; the counter electrode is PET-ITO; the electrolyte layer is located between the working electrode and the counter electrode; the edges of the fast-response flexible electrochromic device are encapsulated with resin.

[0006] CN113838680A discloses a wearable, fully flexible solid-state electrochromic supercapacitor and its fabrication method, mainly addressing the problems of poor flexibility, poor energy storage effect, and difficulty in achieving wearability in existing supercapacitors. From bottom to top, it includes a lower current collector, a first active layer, a gel polymer electrolyte layer, a second active layer, and an upper current collector. Both the upper and lower current collectors are composed of a flexible substrate and silver nanowire electrodes, with the silver nanowire electrodes coated on the flexible substrate. The active layer uses a conjugated polymer material to achieve electrochromic functionality, and a portion of the conjugated polymer is embedded in the mesh-like pores of the silver nanowire electrodes, forming a silver nanowire-conjugated polymer composite 3D electrode. This invention improves the mechanical flexibility and electrochemical performance of the supercapacitor, achieving full flexibility, wearability, and visible energy levels, and can be used to provide power for wearable electronic devices.

[0007] While the aforementioned electrochromic devices have improved the performance of wearable devices to some extent, the lightweight design requirements of electrochromic sheets for smart wearable devices also present new challenges: requirements for cycle stability, color-changing speed, thinness, transparency, and low power consumption. Traditional electrochromic sheets, due to their material properties (NiO, WO3), have certain colors and poor cycle stability, as well as severe degradation of electrical performance, and cannot meet the above requirements. Summary of the Invention

[0008] To overcome the above-mentioned defects, the present invention provides an electrochromic sheet and a preparation method thereof, which can solve the above problems and produce an electrochromic sheet with fast color change, good cycle stability, slow electrical performance decay, and meets the requirements of smart wearable devices.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] An electrochromic sheet, wherein the electrochromic sheet comprises, from bottom to top, a first transparent substrate layer 1, a first transparent conductive layer 2, an electrochromic layer 3, an ion conduction layer 4, a first ion storage layer 5, and a second transparent conductive layer 7, wherein the first transparent conductive layer 2 and the second transparent conductive layer 7 have metal grids, and the ion conduction layer 4 is a solid electrolyte layer formed by vacuum magnetron sputtering of a lithium zinc oxide target and a silicon target.

[0011] The transparent conductive layer itself has resistance. When the electrochromic film fades, due to the surrounding electrodes, the fading speed is often faster near the electrode design and slower at the center. This is because when a fading voltage is applied, the resistance of the transparent conductive layer causes a voltage drop as the voltage travels from the periphery of the electrodes to the center. At this point, V... 中心 <V 四周At this point, the center point will show differences in color change speed and color change transmittance.

[0012] This invention, by designing a metal grid within the first transparent conductive layer 2 and the second transparent conductive layer 7, allows for a denser arrangement near the periphery of the electrodes and a more diffuse arrangement near the center. This results in lower resistance around R when a fading voltage is applied, leading to a smaller voltage drop during voltage transmission. This design method can increase V 中心 ≈V 四周 This results in the electrochromic sheet changing color at the same speed at the center and around the edges, leading to more uniform transmittance.

[0013] Meanwhile, in this invention, the solid electrolyte layer formed by vacuum magnetron sputtering of lithium zinc oxide target and silicon target is the ion conduction layer 4, which makes the electrochromic sheet have excellent color change speed and cycle stability, and slow electrical performance decay. It has good application value in the development and research of smart wearable devices and AR glasses.

[0014] Furthermore, the materials of the formed solid electrolyte layer are Li2ZnSiO4 and Zn. y NbOx composite electrolyte thin film material.

[0015] In this invention, the composite electrolyte formed is a composite electrolyte thin film material of Li₂ZnSiO₄ and ZnNbO₄. By employing this composite electrolyte thin film material in the ion-conducting layer, and doping this composite electrolyte thin film material with niobium, NbO₄ is formed. 3- It will replace part of SiO4 4- NbO4 3- Tetrahedron and SiO4 4- The three-dimensional thin-film crystal structure formed by the connection of common vertices in the tetrahedral structure contains relatively large ion channels, which can provide more effective ion channels for zinc ions and lithium ions, and has higher ionic conductivity. As a result, the color change speed is 3-5 times that of traditional lithium ions, and it has extremely high electrochemical stability.

[0016] In this invention, the parameters x and y of ZnyNbOx in the composite electrolyte film material vary according to the oxygen content, with x preferably ranging from 0.1 to 0.5 and y from 5.3 to 5.8.

[0017] Furthermore, it also includes a second ion storage layer 6, which is located between the first ion storage layer 5 and the second transparent conductive layer 7.

[0018] Furthermore, it also includes a second transparent substrate layer 8, which is located on the side of the second transparent conductive layer 7 away from the second ion storage layer 6.

[0019] In this invention, the thickness of the first transparent conductive layer 2 is 20-1000 nm.

[0020] The thickness of the electrochromic layer 3 is 200 nm to 600 nm.

[0021] The thickness of the ion-conducting layer 4 is 100–300 nm.

[0022] The thickness of the first ion storage layer 5 is 10–300 nm.

[0023] The thickness of the second transparent conductive layer 7 is 20–1000 nm.

[0024] The thickness of the second ion storage layer 6 is 100–300 μm.

[0025] The present invention also provides a method for preparing the electrochromic sheet, the method comprising the following steps:

[0026] Step 1: Prepare the first transparent substrate layer 1

[0027] Using a clean substrate glass as the base and argon and oxygen as the working gases, a first transparent substrate layer 1 was prepared by reactive magnetron co-sputtering using a high-purity Si target.

[0028] Step 2: Prepare the first transparent conductive layer 2, and fabricate a metal grid on this layer.

[0029] First, using argon and oxygen as working gases, and indium tin oxide ceramic target, a first transparent conductive layer 2 is formed on the first transparent substrate 1 by DC reactive sputtering; then, a metal grid is fabricated on this layer to obtain the first transparent conductive layer 2 with the metal grid.

[0030] Step 3: Prepare electrochromic layer 3

[0031] Using argon and oxygen as working gases, and employing tungsten metal and niobium oxide targets, an electrochromic layer 3 is formed on a first transparent conductive layer 2 with a metal grid by sputtering.

[0032] Step 4: Prepare the ion-conducting layer 4

[0033] Using argon and oxygen as working gases, and utilizing lithium zinc oxide and silicon targets, an ion-conducting layer 4 is formed on the electrochromic layer 3 by co-sputtering.

[0034] Step 5: Prepare the first ion storage layer 5

[0035] Using argon and oxygen as working gases, a first ion storage layer 5 is formed on the ion conduction layer 4 by reactive sputtering using a niobium oxide / zinc target.

[0036] Step 6: Prepare the second transparent conductive layer 7, and fabricate a metal grid on this layer.

[0037] Using argon and oxygen as working gases, and employing indium tin oxide ceramic targets, a second transparent conductive layer 7 is formed on the first ion storage layer 5 by DC reactive sputtering; then a metal grid is fabricated on this layer to obtain the electrochromic sheet.

[0038] In the above preparation method, in step 4, when the ion-conducting layer 4 is formed on the electrochromic layer 3 by co-sputtering, the basic parameters are: the base vacuum is 6 × 10⁻⁶. -4 Pa, the flow ratio of argon to oxygen is 5:1.2, the working pressure is 2-3 Pa, the sputtering power of lithium zinc oxide target is controlled at 300W, the sputtering power of silicon target is controlled at 200W, the substrate temperature is 200℃, and a solid electrolyte layer, namely the ion conduction layer 4, is formed.

[0039] In the above preparation method, the metal grid fabrication process in steps 2 and 6 is as follows: after the first transparent conductive layer 2 and the second transparent conductive layer 7 are prepared, a laser etching process is used to etch grooves with designed line width and line length at the corresponding designed arrangement positions. Then, conductive silver paste is filled into the corresponding grooves, flush with the upper edge of the first transparent conductive layer 2 and the second transparent conductive layer 7, and thus the metal grid is obtained.

[0040] In this invention, different circuits can be designed according to the metal grid layout in the first transparent conductive layer 2 and the second transparent conductive layer 7 to achieve the purpose of individually controlling the application of voltage and the defogging effect.

[0041] In this invention, the groove depth can vary from 100 to 300 nm.

[0042] In this invention, screen printing or embossing is used when filling the corresponding grooves with the corresponding materials.

[0043] Furthermore, between steps 5 and 6, a second ion storage layer 6 is prepared by means of: using argon and methane as working gases, and using a niobium oxide composite alloy nickel target, the second ion storage layer 6 is formed on the first ion storage layer 5 by reactive sputtering.

[0044] Specifically, the method for preparing the second ion storage layer 6 is as follows: using argon and methane as working gases, and employing a niobium oxide composite alloy nickel target, the second ion storage layer 6 is formed on the first ion storage layer 5 by reactive sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to methane is 50:1, the working pressure is 0.6 to 1 Pa, the sputtering power is DC 300 W, and the substrate temperature is 350 °C.

[0045] Furthermore, after step 6, the method further includes preparing a second transparent substrate layer 8, which is as follows: using the above-mentioned coated glass as a substrate, argon and oxygen as working gases, and using a Si target, the second transparent substrate layer 8 is formed on the second transparent conductive layer 7 by reactive magnetron co-sputtering.

[0046] Specifically, the method for preparing the second transparent substrate layer 8 is as follows: using the above-mentioned coated glass as a substrate, argon and oxygen as working gases, and utilizing a Si target, the second transparent substrate layer 8 is formed on the second transparent conductive layer 7 by reactive magnetron co-sputtering; the basic parameters are: the base vacuum degree is 6×10⁻⁶. -4 The working pressure is 0.6-1 Pa, the argon to oxygen flow ratio is 40:7, the working pressure is 0.6-1 Pa, the medium frequency bias is applied, and the sputtering power is DC 150W.

[0047] In the preparation method of the present invention described above, the basic parameters in step 1 are: the background vacuum degree is 6×10⁻⁶. -4 The working pressure is 0.6-1 Pa, the argon to oxygen flow ratio is 40:7, the working pressure is 0.6-1 Pa, the medium frequency bias is applied, and the sputtering power is DC 150W.

[0048] In step 2, the basic parameters are: background vacuum level is 6×10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0049] In step 3, the basic parameters are: background vacuum level is 6×10⁻⁶. -4 At a working pressure of 2-3 Pa, with an argon to oxygen flow ratio of 3:0.8, a sputtering power of DC220W, and a substrate temperature of 350℃, a first WO3 composite thin film color-changing layer is obtained by deposition; at a substrate temperature of 20℃, a second deposition is performed to obtain a second WO3 composite thin film color-changing layer, and thus an electrochromic layer 3 is obtained.

[0050] In step 5, the basic parameters are: background vacuum level is 6×10⁻⁶. -4 The working pressure is 2-3 Pa, the argon to oxygen flow ratio is 25:2, the sputtering power is DC250W, and the substrate temperature is room temperature.

[0051] In step 6, the basic parameters are: background vacuum level is 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0052] In this invention, the lithium zinc oxide target material used is made of lithium zinc oxide, and the preparation method is the same as that of commonly used zirconium targets, nickel targets, iron targets, etc. in the field.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] The electrochromic sheet of this invention has excellent color-changing speed and cycle stability, and slow electrical performance decay, making it valuable for the development and research of smart wearable devices and AR glasses. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the structure of the electrochromic sheet prepared in Embodiment 1 of the present invention;

[0056] Figure 2 This is a schematic diagram of the structure of the electrochromic sheet prepared in Embodiment 2 of the present invention;

[0057] Figure 3 This is a schematic diagram of the structure of the electrochromic sheet prepared in Embodiment 3 of the present invention;

[0058] Figure 4 The first graph shows the electrical performance cycle life test of the electrochromic sheet prepared in comparison.

[0059] Figure 5 The graph shows the electrical performance of the electrochromic sheet prepared in comparison after 50,000 cycles of cycle life testing.

[0060] Figure 6 This is a graph showing the first cycle life test of the electrical performance of the electrochromic sheet prepared in Example 1 of the present invention.

[0061] Figure 7 This is a graph showing the 50,000th cycle of the electrical performance cycle life test of the electrochromic sheet prepared in Example 1 of the present invention. Detailed Implementation

[0062] The following are specific embodiments of the present invention. These embodiments are intended to further describe the present invention and are not intended to limit the present invention.

[0063] Example 1

[0064] like Figure 1 As shown, the electrochromic sheet of this embodiment includes, from bottom to top, a first transparent substrate layer 1, a first transparent conductive layer 2, an electrochromic layer 3, an ion conduction layer 4, a first ion storage layer 5, and a second transparent conductive layer 7, wherein the first transparent conductive layer 2 and the second transparent conductive layer 7 have metal grids.

[0065] The method for preparing the electrochromic sheet in this embodiment includes the following steps:

[0066] Step 1: Prepare the first transparent substrate layer 1

[0067] Using a clean substrate glass as the base and argon and oxygen as the working gases, a first transparent substrate layer 1 was prepared by reactive magnetron sputtering using a high-purity Si target. The basic parameters were: a base vacuum of 6 × 10⁻⁶. -4 The working pressure is 0.6-1 Pa, the argon to oxygen flow ratio is 40:7, the working pressure is 0.6-1 Pa, the medium frequency bias is applied, and the sputtering power is DC 150W.

[0068] Step 2: Prepare the first transparent conductive layer 2, and fabricate a metal grid on this layer.

[0069] First, using argon and oxygen as working gases, and employing an indium tin oxide ceramic target, a first transparent conductive layer 2 with a thickness of 800 nm is formed on the first transparent substrate 1 by DC reactive sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0070] Then, a laser etching process is used to etch grooves with the designed line width and line length at the corresponding arrangement positions. Then, conductive silver paste is filled into the corresponding grooves, flush with the upper edge of the first transparent conductive layer 2, to obtain the first transparent conductive layer 2 with metal grid.

[0071] Step 3: Prepare electrochromic layer 3

[0072] Using argon and oxygen as working gases, and employing tungsten and niobium oxide targets, an electrochromic layer 3 with a thickness of 450 nm is formed on a first transparent conductive layer 2 with a metal grid by sputtering. The basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 At a working pressure of 2-3 Pa, with an argon to oxygen flow ratio of 3:0.8, a sputtering power of DC220W, and a substrate temperature of 350℃, a first WO3 composite thin film color-changing layer is obtained by deposition; at a substrate temperature of 20℃, a second deposition is performed to obtain a second WO3 composite thin film color-changing layer, and thus an electrochromic layer 3 is obtained.

[0073] Step 4: Prepare the ion-conducting layer 4

[0074] Using argon and oxygen as working gases, and employing lithium zinc oxide and silicon targets, an ion-conducting layer 4 with a thickness of 100 nm was formed on the electrochromic layer 3 via co-sputtering; the basic parameters were: a base vacuum of 6 × 10⁻⁶. -4Pa, the flow ratio of argon to oxygen is 5:1.2, the working pressure is 2-3 Pa, the sputtering power of lithium zinc oxide target is controlled at 300W, the sputtering power of silicon target is controlled at 200W, the substrate temperature is 200℃, and a solid electrolyte layer, namely the ion conduction layer 4, is formed.

[0075] Step 5: Prepare the first ion storage layer 5

[0076] Using argon and oxygen as working gases, a first ion storage layer 5 with a thickness of 280 nm is formed on the ion conduction layer 4 by reactive sputtering using a niobium oxide / zinc target; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The working pressure is 2-3 Pa, the argon to oxygen flow ratio is 25:2, the sputtering power is DC250W, and the substrate temperature is room temperature.

[0077] Step 6: Prepare the second transparent conductive layer 7, and fabricate a metal grid on this layer.

[0078] First, using argon and oxygen as working gases, and employing an indium tin oxide ceramic target, a second transparent conductive layer 7 with a thickness of 800 nm is formed on the first ion storage layer 5 by DC reactive sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0079] Then, a laser etching process is used to etch grooves with the designed line width and length at the corresponding arrangement positions. Then, conductive silver paste is filled into the corresponding grooves, flush with the upper edge of the first transparent conductive layer 7, thus obtaining the electrochromic sheet.

[0080] Example 2

[0081] like Figure 2 As shown, the electrochromic sheet of this embodiment includes, from bottom to top, a first transparent substrate layer 1, a first transparent conductive layer 2, an electrochromic layer 3, an ion conducting layer 4, a first ion storage layer 5, a second ion storage layer 6, and a second transparent conductive layer 7, wherein the first transparent conductive layer 2 and the second transparent conductive layer 7 have metal grids.

[0082] The method for preparing the electrochromic sheet in this embodiment includes the following steps:

[0083] Step 1: Prepare the first transparent substrate layer 1

[0084] Using a clean substrate glass as the base and argon and oxygen as the working gases, a first transparent substrate layer 1 was prepared by reactive magnetron sputtering using a high-purity Si target. The basic parameters were: a base vacuum of 6 × 10⁻⁶. -4The working pressure is 0.6-1 Pa, the argon to oxygen flow ratio is 40:7, the working pressure is 0.6-1 Pa, the medium frequency bias is applied, and the sputtering power is DC 150W.

[0085] Step 2: Prepare the first transparent conductive layer 2, and fabricate a metal grid on this layer.

[0086] First, using argon and oxygen as working gases, and employing an indium tin oxide ceramic target, a first transparent conductive layer 2 with a thickness of 800 nm is formed on the first transparent substrate 1 by DC reactive sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0087] Then, a laser etching process is used to etch grooves with the designed line width and line length at the corresponding arrangement positions. Then, conductive silver paste is filled into the corresponding grooves, flush with the upper edge of the first transparent conductive layer 2, to obtain the first transparent conductive layer 2 with metal grid.

[0088] Step 3: Prepare electrochromic layer 3

[0089] Using argon and oxygen as working gases, and employing tungsten and niobium oxide targets, an electrochromic layer 3 with a thickness of 450 nm is formed on a first transparent conductive layer 2 with a metal grid by sputtering. The basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 At a working pressure of 2-3 Pa, with an argon to oxygen flow ratio of 3:0.8, a sputtering power of DC220W, and a substrate temperature of 350℃, a first WO3 composite thin film color-changing layer is obtained by deposition; at a substrate temperature of 20℃, a second deposition is performed to obtain a second WO3 composite thin film color-changing layer, and thus an electrochromic layer 3 is obtained.

[0090] Step 4: Prepare the ion-conducting layer 4

[0091] Using argon and oxygen as working gases, and employing lithium zinc oxide and silicon targets, an ion-conducting layer 4 with a thickness of 100 nm was formed on the electrochromic layer 3 via co-sputtering; the basic parameters were: a base vacuum of 6 × 10⁻⁶. -4 Pa, the flow ratio of argon to oxygen is 5:1.2, the working pressure is 2-3 Pa, the sputtering power of lithium zinc oxide target is controlled at 300W, the sputtering power of silicon target is controlled at 200W, the substrate temperature is 200℃, and a solid electrolyte layer, namely the ion conduction layer 4, is formed.

[0092] Step 5: Prepare the first ion storage layer 5

[0093] Using argon and oxygen as working gases, a first ion storage layer 5 with a thickness of 280 nm is formed on the ion conduction layer 4 by reactive sputtering using a niobium oxide / zinc target; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The working pressure is 2-3 Pa, the argon to oxygen flow ratio is 25:2, the sputtering power is DC250W, and the substrate temperature is room temperature.

[0094] Step 6: Prepare the second ion storage layer 6

[0095] Using argon and methane as working gases, a second ion storage layer 6 with a thickness of 280 nm is formed on the first ion storage layer 5 by reactive sputtering using a niobium oxide composite alloy nickel target. The basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to methane is 50:1, the working pressure is 0.6 to 1 Pa, the sputtering power is DC 300 W, and the substrate temperature is 350 °C.

[0096] Step 7: Prepare the second transparent conductive layer 7, and fabricate a metal grid on this layer.

[0097] First, using argon and oxygen as working gases, and employing an indium tin oxide ceramic target, a second transparent conductive layer 7 with a thickness of 800 nm is formed on the second ion storage layer 6 by DC reactive sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0098] Then, a laser etching process is used to etch grooves with the designed line width and length at the corresponding arrangement positions. Then, conductive silver paste is filled into the corresponding grooves, flush with the upper edge of the first transparent conductive layer 7, thus obtaining the electrochromic sheet.

[0099] Example 3

[0100] The electrochromic sheet provided in this embodiment further includes a second transparent substrate layer 8, based on embodiment 2. The second transparent substrate layer 8 is located on the side of the second transparent conductive layer 7 away from the second ion storage layer 6. For example... Figure 3 As shown.

[0101] The method for preparing the electrochromic sheet in this embodiment is the same as in Embodiment 2, except that after preparing the second transparent conductive layer 7 with a metal grid, the following steps are also included:

[0102] Step 8: Prepare the second transparent substrate layer.

[0103] Using the aforementioned coated glass as a substrate, and argon and oxygen as working gases, a second transparent substrate layer 8 is formed on a second transparent conductive layer 7 with a metal grid using a Si target and reactive magnetron co-sputtering. The basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0104] Comparative Example

[0105] The electrochromic sheet prepared in this comparative example has the same structure as in Example 1, except that the first transparent conductive layer 2 and the second transparent conductive layer 7 do not have a metal grid, and the ion-conducting layer 4 is a lithium tungstate electrolyte layer formed by magnetron sputtering using lithium metal and tungsten metal as targets. Its preparation method includes the following steps:

[0106] Step 1: Prepare the first transparent substrate layer 1

[0107] Using a clean substrate glass as the base and argon and oxygen as the working gases, a first transparent substrate layer 1 was prepared by reactive magnetron sputtering using a high-purity Si target. The basic parameters were: a base vacuum of 6 × 10⁻⁶. -4 The working pressure is 0.6-1 Pa, the argon to oxygen flow ratio is 40:7, the working pressure is 0.6-1 Pa, the medium frequency bias is applied, and the sputtering power is DC 150W.

[0108] Step 2: Prepare the first transparent conductive layer 2

[0109] Using argon and oxygen as working gases and indium tin oxide ceramic target, a first transparent conductive layer 2 with a thickness of 800 nm is formed on the first transparent substrate 1 by DC reactive sputtering; the basic parameters are: base vacuum level of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0110] Step 3: Prepare electrochromic layer 3

[0111] Using argon and oxygen as working gases, and employing tungsten and niobium oxide targets, an electrochromic layer 3 with a thickness of 450 nm is formed on the first transparent conductive layer 2 by sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 At a working pressure of 2-3 Pa, with an argon to oxygen flow ratio of 3:0.8, a sputtering power of DC220W, and a substrate temperature of 350℃, a first WO3 composite thin film color-changing layer is obtained by deposition; at a substrate temperature of 20℃, a second deposition is performed to obtain a second WO3 composite thin film color-changing layer, and thus an electrochromic layer 3 is obtained.

[0112] Step 4: Prepare the ion-conducting layer 4

[0113] Using argon and oxygen as working gases, and employing lithium and tungsten metal targets, a 100 nm thick lithium tungstate electrolyte layer, i.e., the ion conduction layer 4, is formed on the electrochromic layer 3 by sputtering. The basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 At a working pressure of 2–3 Pa, an argon to oxygen flow ratio of 3:0.8, a sputtering power of DC 220 W, and a substrate temperature of 350 °C, a first WO3 composite thin film color-changing layer was deposited; a second deposition was performed at a substrate temperature of 20 °C to obtain a second WO3 composite thin film color-changing layer. The substrate temperature was then adjusted to a background vacuum of 6 × 10⁻⁶ Pa. -4 Pa, the flow ratio of argon to oxygen is 25:2, the working pressure is 2-3 Pa, the sputtering power is DC250W, the substrate temperature is room temperature, and the deposition is performed once to form a lithium tungstate electrolyte layer, namely the ion conduction layer 4.

[0114] Step 5: Prepare the first ion storage layer 5

[0115] Using argon and oxygen as working gases, a first ion storage layer 5 with a thickness of 280 nm is formed on the ion conduction layer 4 using niobium oxide; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The working pressure is 2-3 Pa, the argon to oxygen flow ratio is 25:2, the sputtering power is DC250W, and the substrate temperature is room temperature.

[0116] Step 6: Prepare the second transparent conductive layer 7

[0117] Using argon and oxygen as working gases, and employing indium tin oxide ceramic targets, a second transparent conductive layer 7 with a thickness of 800 nm is formed on the first ion storage layer 5 by DC reactive sputtering; the basic parameters are: a base vacuum of 6 × 10⁻⁶. -4 The flow rate ratio of argon to oxygen was 49.5:0.5, the working pressure was 0.3–1.0 Pa, the sputtering power was DC 130 W, and the substrate temperature was room temperature.

[0118] Experimental Example 1

[0119] This test example demonstrates the electrical and cycling performance of the electrochromic sheets prepared according to the present invention and the comparative example.

[0120] 1. Experimental equipment

[0121] Gamry electrochemical workstation model 1010E.

[0122] 2. Experimental Methods

[0123] Cyclic life tests were performed using a time-ampere generator in an electrochemical workstation.

[0124] 3. Sample

[0125] Experimental sample: Electrochromic film prepared in Example 1 of this invention;

[0126] Control sample: Electrochromic film prepared in comparison.

[0127] 4. Experimental Procedure

[0128] (1) Solder a 20-30cm long copper wire to the positive and negative poles of the sample;

[0129] (2) Use the negative electrode of the sample as the working electrode and the positive electrode of the sample as the counter electrode, and connect them to the corresponding electrode interfaces of the electrochemical workstation respectively.

[0130] (3) Turn on the experimental equipment and fill in the experimental test conditions: Color change step voltage: 1.9V applied for 5s, then 1.35V applied for 30s; Fading voltage: -1.9V applied for 10s;

[0131] (4) Set the number of test cycles to 1 or 50,000. Calculate the photoelectric performance data frequency according to the sampling frequency of 1 or 50,000 times. The photoelectric performance data includes, but is not limited to: current value before and after the experiment, range of transmittance change, fading time, etc.

[0132] (5) Run the preset program to start the loop test and repeat step 4 until the sample is damaged.

[0133] 5. Experimental Results

[0134] The experimental results are shown in Figures 4 to 7 As shown in Table 1:

[0135] Table 1

[0136]

[0137] The experimental results in Table 1 show that:

[0138] (1) The color change time of the experimental sample was increased by 46.6% and the fading time was increased by 25% compared with the control sample;

[0139] (2) The control sample was tested for 50,000 cycles to achieve the same range of transmittance change. The color change time decreased by 25% and the fading time decreased by 25%.

[0140] (3) The experimental sample was tested for 50,000 cycles to achieve the same range of transmittance change. The color change time decayed by 12.5% ​​and the fading time decayed by 16%.

[0141] (4) The experimental sample has a 50% higher cycle life than the control sample, but its electrical performance is reduced to half of that of the existing process. Therefore, the experimental sample is far superior to the control sample.

Claims

1. An electrochromic film, characterized in that, The electrochromic sheet comprises, from bottom to top, a first transparent substrate layer (1), a first transparent conductive layer (2), an electrochromic layer (3), an ion-conducting layer (4), a first ion storage layer (5), and a second transparent conductive layer (7). The first transparent conductive layer (2) and the second transparent conductive layer (7) have metal grids. The ion-conducting layer (4) is a solid electrolyte layer formed by vacuum magnetron sputtering of lithium zinc oxide target and silicon target. The solid electrolyte layer is made of Li2ZnSiO4 and Zn. y NbOx composite electrolyte thin film material, where x takes values ​​between 0.1 and 0.5, and y takes values ​​between 5.3 and 5.8; Using argon and oxygen as working gases, and employing tungsten metal and niobium oxide targets, the electrochromic layer (3) is formed on a first transparent conductive layer (2) with a metal grid by sputtering. Using argon and oxygen as working gases, the first ion storage layer (5) is formed on the ion conduction layer (4) by reactive sputtering using niobium oxide / zinc target material.

2. The electrochromic sheet according to claim 1, characterized in that, It also includes a second ion storage layer (6), which is located between the first ion storage layer (5) and the second transparent conductive layer (7).

3. The electrochromic sheet according to claim 2, characterized in that, It also includes a second transparent substrate layer (8), which is located on the side of the second transparent conductive layer (7) away from the second ion storage layer (6).

4. A method for preparing the electrochromic sheet according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: Step 1: Prepare the first transparent substrate layer (1) Using clean substrate glass as the base and argon and oxygen as the working gases, a first transparent substrate layer was prepared by reactive magnetron sputtering using a high-purity Si target (1). Step 2: Prepare the first transparent conductive layer (2) and fabricate a metal grid on this layer. First, using argon and oxygen as working gases, and indium tin oxide ceramic target, a first transparent conductive layer (2) is formed on the first transparent substrate layer (1) by DC reactive sputtering; then, a metal grid is fabricated on this layer to obtain the first transparent conductive layer (2) with the metal grid. Step 3: Prepare the electrochromic layer (3) Using argon and oxygen as working gases, and with tungsten metal and niobium oxide targets, an electrochromic layer (3) is formed on a first transparent conductive layer (2) with a metal grid by sputtering. Step 4: Prepare the ion-conducting layer (4) Using argon and oxygen as working gases, and with lithium zinc oxide and silicon targets, an ion-conducting layer (4) is formed on the electrochromic layer (3) by co-sputtering. Step 5: Prepare the first ion storage layer (5) Using argon and oxygen as working gases, a first ion storage layer (5) is formed on the ion conduction layer (4) by reactive sputtering using a niobium oxide / zinc target. Step 6: Prepare the second transparent conductive layer (7) and fabricate a metal grid on this layer. First, using argon and oxygen as working gases, and indium tin oxide ceramic target, a second transparent conductive layer (7) is formed on the first ion storage layer (5) by DC reactive sputtering; then a metal grid is fabricated on this layer to obtain the electrochromic sheet.

5. The preparation method according to claim 4, characterized in that, In step 4, when the ion-conducting layer (4) is formed on the electrochromic layer (3) by co-sputtering, the basic parameters are: the background vacuum is 6×10⁻⁶. -4 Pa, the flow ratio of argon to oxygen is 5:1.2, the working pressure is 2-3 Pa, the sputtering power of lithium zinc oxide target is controlled at 300W, the sputtering power of silicon target is controlled at 200W, the substrate temperature is 200℃, and a solid electrolyte layer, namely the ion conduction layer (4), is formed.

6. The preparation method according to claim 5, characterized in that, In steps 2 and 6, the manufacturing process of the metal grid is as follows: after the first transparent conductive layer (2) and the second transparent conductive layer (7) are prepared, the grooves with the designed line width and line length are etched at the corresponding designed arrangement positions using laser etching process. Then, conductive silver paste is filled into the corresponding grooves and flush with the upper edge of the first transparent conductive layer (2) and the second transparent conductive layer (7) to obtain the desired result.

7. The preparation method according to any one of claims 4-6, characterized in that, Between steps 5 and 6, a second ion storage layer (6) is prepared by means of: using argon and methane as working gases, and using niobium oxide composite alloy nickel target material, the second ion storage layer (6) is formed on the first ion storage layer (5) by reactive sputtering.

8. The preparation method according to claim 7, characterized in that, Step 6 includes the preparation of a second transparent substrate layer (8), which is carried out by using argon and oxygen as working gases and Si target material to form the second transparent substrate layer (8) on the second transparent conductive layer (7) by reactive magnetron co-sputtering.

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