Manufacturing method of electrochromic glass capable of prolonging memory effect
By doping molybdenum and titanium into electrochromic glass, annealing, and using solid electrolyte LiTaO3, the thickness and charge capacity matching of the ITO electrode film were optimized, solving the memory effect problem of electrochromic glass and achieving significant life extension and stability improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-24
- Publication Date
- 2026-03-31
AI Technical Summary
Existing electrochromic glass exhibits a memory effect after multiple coloring-fading cycles, making it impossible to fully recover to its initial transparent state. Furthermore, the colored state is short-lived after power is turned off, leading to optical performance degradation, slower color-changing response speed, and increased energy consumption, which seriously affects its long-term stability and commercial applications.
By doping molybdenum and titanium into the electrochromic layer and combining it with annealing, the thickness of the ITO electrode film is optimized using the high-performance solid electrolyte LiTaO3, and the charge capacity of the anode and cathode is precisely matched to form a stable charge balance, suppressing ion residue and irreversible reactions.
It significantly extends the memory effect lifespan of electrochromic glass, improves cycle stability and lifespan, and maintains a long-term stable optical modulation range and fast response speed.
Smart Images
Figure CN121763620A_ABST
Abstract
Description
Technical Field
[0001] This invention discloses a method for manufacturing electrochromic glass that extends the memory effect. Specifically, it relates to a method that significantly extends the memory effect of electrochromic glass and improves its cycle stability and service life through material modification, interface control and charge balance design, and belongs to the field of electrochromic technology. Background Technology
[0002] Electrochromic glass is a smart material that can reversibly change its optical properties (such as transmittance and reflectance) under the action of an external electric field. It has broad application prospects in fields such as building energy-saving windows, automotive anti-glare rearview mirrors, and display devices.
[0003] However, existing electrochromic glasses generally suffer from the "memory effect" problem. After multiple coloring-fading cycles, the device will be unable to fully recover to its initial transparent state, and the color state will be short-lived after power is turned off, resulting in optical performance degradation, slower color-changing response speed, and increased energy consumption. This seriously restricts the long-term stability and commercial application of such products.
[0004] The memory effect can be attributed to several factors, including: (1) Ion capture and irreversible reaction: In an electrochromic layer (e.g., WO3), injected ions (e.g., Li) + It may be trapped deep in lattice defects or interfaces, making it difficult to completely escape under the action of a reverse electric field, which will lead to residual coloration.
[0005] (2) The electrolyte / electrochromic layer interface is unstable: Traditional liquid electrolytes are prone to leakage and volatilization, and the interfacial side reactions with electrode materials will hinder the reversible transport of ions; although solid electrolytes have better stability, their ionic conductivity is low, and the interfacial contact problem with electrode materials is more prominent.
[0006] (3) Charge capacity mismatch: The charge capacity mismatch between the electrochromic layer (cathode coloring material) and the counter electrode layer (anode coloring material or ion storage layer) will cause some ions to be unable to be fully accepted or released by the counter electrode during cycling, resulting in ion accumulation at the interface, which will aggravate the memory effect.
[0007] (4) Electrochromic layer structural defects: Although amorphous WO3 has a high ion diffusion coefficient, it has poor structural stability and is prone to structural rearrangement during cycling, generating more irreversible ion trapping sites.
[0008] While existing technologies have attempted to mitigate the memory effect by optimizing electrolyte composition and improving thin-film fabrication processes, their effectiveness is limited and they fail to fundamentally address the performance degradation problem under long-term cycling. Therefore, developing a method to systematically and effectively extend the memory effect of electrochromic glass is a pressing technical challenge in this field. Summary of the Invention
[0009] To address the "memory effect" problem commonly found in existing electrochromic glasses, this invention provides a method for manufacturing electrochromic glasses that extends the memory effect. This method employs multi-dimensional synergistic optimization, including elemental doping and annealing of the electrochromic layer to enhance its structural stability and ion reversibility; using a high-performance solid electrolyte LiTaO3 to ensure a stable ion transport interface; modifying the electrodes with V doping to enhance their ion storage capacity; optimizing the ITO electrode film thickness to improve electric field distribution and interfacial contact; and precisely matching the anode and cathode charge capacities to eliminate ion residue. This fundamentally suppresses the memory effect, thereby achieving a method that significantly extends the memory effect of electrochromic glasses, improves cycle stability, and extends service life.
[0010] The technical solution adopted by this invention to solve its technical problem is: a method for manufacturing electrochromic glass that prolongs the memory effect, the manufacturing method comprising the following steps: Step S1, Substrate preparation: Use glass as the substrate and clean the substrate; Step S2, Underlying ITO preparation: An ITO film is deposited on the substrate as the underlying ITO film, with a thickness of 80~120nm. Step S3, Electrochromic layer preparation: The electrochromic layer is made of tungsten trioxide as the matrix material, and molybdenum and titanium are doped into WO3. The doping concentration is: the atomic percentage of Mo is 1-5%, the atomic percentage of Ti is 0.5-3%, and the thickness of the electrochromic layer is 300-600nm. Step S4, Annealing: Annealing is performed in an inert atmosphere at a temperature of 300-450℃ for 1-3 hours. Step S5, Electrolyte layer preparation: An electrolyte layer is generated on the electrochromic layer. The electrolyte layer uses lithium tantalate as a solid electrolyte layer with a thickness of 600-1000 nm. Step S6, Ion storage layer preparation: The ion storage layer is deposited on the electrolyte layer using nickel oxide as the substrate material, and V element is added to NiO to achieve doping modification, with a total thickness of 300-600 nm. Step S7, Top ITO preparation: Deposit an ITO film on the ion storage layer as the top ITO film, with a thickness of 80-240 nm; Step S8, Packaging: The device is packaged in a dry environment to form the finished product.
[0011] The technical solution adopted by the present invention to solve its technical problem further includes: In step S2, the underlying ITO film is generated by magnetron sputtering deposition.
[0012] In step S3, WO3, Mo and Ti are used as sources, and magnetron sputtering deposition is performed using co-sputtering method to deposit WO3, Mo and Ti onto the underlying ITO film.
[0013] In step S3, deposition is carried out in an argon atmosphere.
[0014] In step S4, the inert atmosphere is nitrogen or argon.
[0015] In step S5, radio frequency magnetron sputtering is used to deposit LiTaO3N using a LiTaO3 target as the source under an argon (Ar) atmosphere and a small amount of nitrogen (N2) atmosphere. x A thin film with a thickness of 1 μm.
[0016] In step S6, the amount of V doping is 5-15% of the molar number of Ni atoms in NiO.
[0017] The thickness ratio of the bottom ITO film to the top ITO film is 1:1 to 1:2.
[0018] The difference in charge capacity between the electrochromic layer and the ion storage layer is within ±5%.
[0019] The beneficial effects of the present invention are: (1) Significantly prolonging the lifetime of the memory effect: By co-doping WO3 with Mo and Ti and annealing treatment, the structural stability and ion reversibility of the electrochromic layer are greatly improved, fundamentally reducing ion trapping and irreversible reactions.
[0020] (2) High interface stability: The use of solid electrolyte avoids the drawbacks of liquid electrolyte and provides a stable and reliable ion transport channel.
[0021] (3) Good charge balance: NiO doping with V improves the ion storage capacity of the electrode. Combined with the precise matching of the charge capacity of the anode and cathode, it ensures the complete reversible migration of ions during the cycle and effectively suppresses ion residue.
[0022] (4) Uniform electric field distribution: The optimized matching of ITO film thickness improves the electric field distribution of the device and promotes the uniform insertion and extraction of ions.
[0023] (5) Excellent overall performance: Through the synergistic effect of the above-mentioned multiple technical means, the present invention can significantly extend the cycle life of electrochromic glass, reduce the memory effect, maintain a long-term stable optical modulation range and fast response speed, and has important practical application value.
[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description
[0025] Figure 1 This is a partial cross-sectional structural diagram of the electrochromic glass device according to an embodiment of the present invention.
[0026] Figure 2 This is a process flow diagram of an embodiment of the present invention.
[0027] In the figure, 1-substrate, 2-bottom ITO film, 3-electrochromic layer, 4-electrolyte layer, 5-ion storage layer, 6-top ITO film. Detailed Implementation
[0028] This embodiment is a preferred embodiment of the present invention. All other embodiments that are the same as or similar to this embodiment in principle and basic structure are within the protection scope of the present invention.
[0029] Please refer to the appendix for details. Figure 1 and attached Figure 2 This invention primarily protects a method for manufacturing electrochromic glass that extends the memory effect, the method mainly comprising the following steps: Step S1, Substrate preparation: In this invention, glass is used as substrate 1. The preparation stage is to clean substrate 1 to make its surface clean.
[0030] Step S2, Preparation of the bottom ITO layer: An ITO film (abbreviation for Indium Tin Oxide) is deposited on the substrate 1. The thickness of the bottom ITO film 2 is 80~120nm, which is used as the bottom conductive layer. In this embodiment, the bottom ITO film 2 is formed by magnetron sputtering deposition, preferably by direct current (DC) magnetron sputtering deposition.
[0031] Step S3, Electrochromic Layer Preparation: The electrochromic layer 3 is made of tungsten trioxide (WO3) as the matrix material. In this embodiment, molybdenum (Mo) and titanium (Ti) are doped into WO3 to achieve elemental doping. The preferred doping concentrations are: 1-5% atomic percentage of Mo and 0.5-3% atomic percentage of Ti. Mo doping can adjust the band structure of WO3, improve its conductivity, and reduce charge transport resistance; Ti doping can stabilize the lattice structure of WO3, suppress structural distortion during cycling, and reduce ion trapping sites.
[0032] In this embodiment, WO3, Mo, and Ti targets are used as sources, and magnetron sputtering deposition is performed using a co-sputtering method to attach WO3, Mo, and Ti onto the underlying ITO film. This embodiment uses multiple independent targets for co-sputtering, and the proportions of each component in the film can be precisely adjusted in real time by controlling the sputtering power and sputtering time of each target. In this embodiment, deposition is carried out in an Ar (argon) atmosphere.
[0033] In this embodiment, the thickness of the electrochromic layer 3 is 300-600 nm.
[0034] Step S4, Annealing: After depositing the WO3:Mo,Ti thin film, annealing is performed in an inert atmosphere (such as nitrogen or argon). The preferred annealing temperature is 300-450℃, and the annealing time is 1-3 hours. Annealing can eliminate internal stress in the film, reduce defect density, promote the formation of a more stable microstructure, thereby improving the reversible insertion / extraction capability of ions and effectively suppressing the memory effect.
[0035] Step S5: Electrolyte layer preparation: An electrolyte layer 4 is formed on the electrochromic layer 3. In this embodiment, lithium tantalate (LiTaO3) is used as the solid electrolyte layer 4. LiTaO3 has excellent chemical stability, a wide electrochemical window, and high ionic conductivity, which can form a stable interface with the electrode material, avoiding leakage and side reactions of the liquid electrolyte and providing a reliable guarantee for reversible ion transport.
[0036] Electrolyte layer 4 was formed using radio frequency (RF) magnetron sputtering with a LiTaO3 target as the source, and LiTaO3N was deposited in an atmosphere of argon (Ar) and a small amount of nitrogen (N2). x The (nitrogen-doped lithium tantalate) film has a thickness of approximately 800-1200 nm. In this embodiment, the volume ratio of argon (Ar) to nitrogen (N2) is 10:1, and the amount of nitrogen (N2) introduced is 5-10 SCCM. In specific implementation, the specific amount of nitrogen (N2) introduced can be adjusted according to actual needs.
[0037] Step S6, Ion storage layer preparation: The ion storage layer 5 is deposited on the electrolyte layer 4 using nickel oxide (NiO) as the substrate material for ion storage.
[0038] In this embodiment, vanadium (V) is incorporated into NiO to achieve doping modification. V doping significantly improves the ion storage capacity and conductivity of NiO, enabling it to more effectively store and release Li⁺ ions during the coloring / fading process, thus better matching the charge requirements of the electrochromic layer 3. The preferred V doping amount is 5-15% of the molar number of Ni atoms in NiO.
[0039] In this embodiment, magnetron sputtering is used to deposit a NiO:V thin film using a NiO target doped with a predetermined amount of V as the source. The thickness is calculated to match the charge capacity of the electrochromic layer 3 (difference <5%). The charge capacities of the electrochromic layer (WO3:Mo,Ti) and the ion storage layer (NiO:V) are precisely designed to ensure that their charge capacities are essentially equal or very close (e.g., the difference is controlled within ±5%). This can be achieved by controlling the thickness and density of each functional layer. This charge capacity matching ensures that the Li₂ extracted from the electrochromic layer 3 during coloring and fading processes is effectively controlled. + Ions can be fully accepted by the ion storage layer, and vice versa, fundamentally eliminating ion residue and memory effect caused by charge imbalance.
[0040] Step S7, Top ITO preparation: An ITO film (abbreviation for Indium Tin Oxide) is deposited on the ion storage layer 5. The thickness of the top ITO film 6 is 80-240nm, which is used as the top conductive layer. In this embodiment, the top ITO film 6 is formed by magnetron sputtering deposition, preferably by direct current (DC) magnetron sputtering deposition.
[0041] In this embodiment, the film thicknesses of the bottom ITO layer (closest to the glass substrate) and the top ITO layer (outermost layer) need to be optimized and matched. By adjusting their thicknesses, the electric field distribution of the entire device can be balanced, charge accumulation at the interface can be reduced, and current uniformity can be improved, thereby facilitating the uniform insertion and extraction of ions. The preferred film thickness matching scheme is: the bottom ITO film 2 has a thickness of 80-120 nm, and the top ITO film 6 has a thickness of 80-240 nm.
[0042] Step S8, Packaging: The device is packaged in a dry environment to form the finished product.
[0043] The invention will be further described below with several specific examples: Example 1:
[0044] Step S1: Substrate preparation: Clean the glass substrate and deposit the bottom layer ITO by magnetron sputtering on it, with a film thickness of 100nm.
[0045] Step S2, Electrochromic Layer Preparation: A WO3:Mo (3 at%), Ti (1.5 at%) thin film with a thickness of approximately 400 nm was deposited using a co-sputtering method with WO3, Mo, and Ti targets as sources under an Ar atmosphere. Subsequently, the film was annealed at 350 °C for 2 hours in a N2 atmosphere.
[0046] Step S3, Electrolyte Layer Preparation: LiTaO3N was deposited using radio frequency magnetron sputtering with a LiTaO3 target as the source under an Ar, N2 atmosphere. xThe film has a thickness of approximately 1 μm.
[0047] Step S4, Preparation of ion storage layer: NiO:V thin film is deposited using magnetron sputtering with a NiO target doped with 10 at% V as the source. The thickness is calculated to match the charge capacity of the electrochromic layer (difference <5%).
[0048] Step S5, Top-layer ITO preparation: Top-layer ITO is deposited on the ion storage layer by magnetron sputtering with a film thickness of 200 nm.
[0049] Step S6, Packaging: Package the device in a dry environment.
[0050] Example 2: This example is similar to Example 1, except that the doping concentration of WO3 is Mo (1 at%), Ti (0.5 at%), the annealing temperature is 450℃, the annealing time is 1 hour, the V doping amount of NiO is 5 at%, the bottom ITO film thickness is 80nm, and the top ITO film thickness is 200nm.
[0051] Example 3: This example is similar to Example 1, except that the WO3 doping concentration is Mo (5 at%), Ti (3 at%), the annealing temperature is 300℃, the annealing time is 3 hours, the NiO V doping amount is 15 at%, the bottom ITO film thickness is 40nm, and the top ITO film thickness is 200nm.
[0052] Comparative Example 1: Using existing technology, pure WO3 was used as the electrochromic layer without doping or annealing; the electrolyte was a conventional liquid electrolyte (LiClO4 / PC); the counter electrode was pure NiO without V doping; the ITO film thickness was not optimized; and the charge capacity was not precisely matched.
[0053] Performance Testing: The changes in visible light transmittance in the colored state of the electrochromic devices prepared in the above embodiments and comparative examples were monitored (characterization of the memory effect, i.e., after applying a voltage of -1.5V for 5 minutes and then disconnecting the power, the time it takes for the visible light transmittance to return to the faded state was observed), and cycle life testing was performed (e.g., 5000 consecutive color-fading cycles). The test results show that: In Comparative Example 1, after 5000 cycles, the transmittance of the faded state decreased from the initial 65% to 55%, and the power-off color memory time was only 0.5 minutes.
[0054] After 5000 cycles, the light transmittance of the faded state in Examples 1 to 3 can still be maintained at more than 90% of the initial value (e.g., in Example 3, the transmittance decreased from 76% to 73%, and the color memory time reached 90 minutes), and the cycle stability is far better than that of Comparative Example 1.
[0055]
[0056] The product prepared by this invention has the following advantages compared with the prior art: (1) Significantly extended memory effect lifetime: Through Mo and Ti co-doping and annealing of WO3, the structural stability and ion reversibility of the electrochromic layer are greatly improved, fundamentally reducing ion trapping and irreversible reactions.
[0057] (2) High interface stability: The use of LiTaO3 solid electrolyte avoids the disadvantages of liquid electrolyte and provides a stable and reliable ion transport channel.
[0058] (3) Good charge balance: NiO doping with V improves the ion storage capacity of the electrode. Combined with the precise matching of the charge capacity of the anode and cathode, it ensures the complete reversible migration of ions during the cycle and effectively suppresses ion residue.
[0059] (4) Uniform electric field distribution: The optimized matching of ITO film thickness improves the electric field distribution of the device and promotes the uniform insertion and extraction of ions.
[0060] (5) Excellent overall performance: Through the synergistic effect of the above-mentioned multiple technical means, the present invention can significantly extend the cycle life of electrochromic glass, enhance the memory effect, maintain a long-term stable optical modulation range and fast response speed, and has important practical application value.
Claims
1. A method for manufacturing electrochromic glass with extended memory effect, characterized in that: The manufacturing method includes the following steps: Step S1, Substrate preparation: Use glass as the substrate and clean the substrate (1); Step S2, Underlying ITO preparation: An ITO film is deposited on the substrate (1) as the underlying ITO film (2), and the thickness of the underlying ITO film (2) is 80~120nm; Step S3, Electrochromic layer preparation: The electrochromic layer (3) is made of tungsten trioxide as the matrix material, and molybdenum and titanium are doped into WO3. The doping concentration is: the atomic percentage of Mo is 1-5%, the atomic percentage of Ti is 0.5-3%, and the thickness of the electrochromic layer (3) is 300-600nm. Step S4, Annealing: Annealing is performed in an inert atmosphere at a temperature of 300-450℃ for 1-3 hours. Step S5, Electrolyte layer preparation: An electrolyte layer (4) is formed on the electrochromic layer (3), and lithium tantalate is used as the solid electrolyte layer in the electrolyte layer (4); Step S6, Preparation of ion storage layer: The ion storage layer (5) is deposited on the electrolyte layer (4) using nickel oxide as the substrate material, and vanadium is added to NiO to achieve doping modification; Step S7, Top ITO preparation: An ITO film is deposited on the ion storage layer (5) as the top ITO film (6), and the thickness of the top ITO film (6) is 80-240 nm; Step S8, Packaging: The device is packaged in a dry environment to form the finished product.
2. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: In step S2, the bottom ITO film (2) is generated by magnetron sputtering deposition.
3. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: In step S3, WO3, Mo and Ti targets are used as sources, and magnetron sputtering deposition is performed by co-sputtering method to deposit WO3, Mo and Ti onto the bottom ITO film (2).
4. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: In step S3, deposition is carried out in an argon atmosphere.
5. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: In step S4, the inert atmosphere is nitrogen or argon.
6. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: In step S5, radio frequency magnetron sputtering is used to deposit LiTaO3N using a LiTaO3 target as the source under an argon (Ar) and nitrogen (N2) atmosphere. x Thin film with a thickness of 800-1200 nm.
7. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: In step S6, the amount of V doping is 5-15% of the molar number of Ni atoms in NiO.
8. The method for manufacturing electrochromic glass with extended memory effect according to claim 1, characterized in that: The difference in charge capacity between the electrochromic layer (3) and the ion storage layer (5) is within ±5%.