Electrochromic device and preparation method and application thereof

Abstract

The application discloses an electrochromic device and a preparation method and application thereof, and relates to the technical field of electrochromic devices. The preparation method comprises the following steps: depositing an electrochromic layer on a first transparent conductive layer, wherein the material of the electrochromic layer is tungsten oxide; depositing an ion conduction layer on the electrochromic layer, wherein the material of the ion conduction layer is tungsten oxide; depositing an ion storage layer on the ion conduction layer, wherein the material of the ion storage layer is nickel tungsten oxide; depositing a lithium ion layer on the ion storage layer for a preset time; depositing a second transparent conductive layer on the lithium ion layer, and sequentially performing primary annealing treatment and secondary annealing treatment, so that lithium ions in the lithium ion layer diffuse to the ion storage layer and reach a preset concentration, thereby obtaining the electrochromic device. Through the synergistic effect of thinning structure, lithium ion concentration regulation and two-step annealing, the device B value is reduced, the overall performance is improved, and the transmittance and electrochromic performance are synergistically maintained.

Description

Technical Field

[0001] This invention relates to the field of electrochromic device technology, specifically to an electrochromic device, its preparation method, and its application. Background Technology

[0002] Electrochromic devices, capable of reversibly adjusting transmittance under applied voltage, are widely used in smart windows, dimmable lenses, and other fields. Electrochromic lenses typically consist of a multi-layered structure including a transparent conductive layer, an electrochromic layer, an ion-conducting layer, and an ion storage layer. Optical properties are altered through the insertion and extraction of ions between these functional layers. However, in existing technologies, electrochromic lenses generally suffer from a yellowish undertone, meaning that the device exhibits a noticeable yellow tint in its uncolored state, causing the overall color to deviate from neutral gray, thus affecting visual comfort and user experience. This problem is usually characterized by the B value in the overall color parameter; a higher B value indicates a more pronounced yellow component.

[0003] To reduce the yellow tint of devices, existing technologies typically employ doping methods by introducing dopants into the functional layer material to modulate its optical absorption properties. However, while these methods can reduce the B-value to some extent, they often introduce new defect states or alter the material's band structure, leading to decreased optical transmittance, deterioration of electrochromic performance, or reduced cycling stability, making it difficult to simultaneously optimize overall color and maintain device performance. Furthermore, some technologies attempt to reduce light absorption by thinning the functional layer of electrochromic devices, thereby improving overall color performance. However, simple thinning usually results in decreased ion storage capacity, reduced color-changing amplitude, and device instability, making it difficult to maintain good electrochromic and optical performance while simultaneously reducing the B-value.

[0004] Therefore, how to maintain high transmittance and stable electrochromic performance while reducing the B value and improving the overall color of electrochromic devices through structural design and process optimization without relying on doping control has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] One objective of the first aspect of this invention is to provide a method for preparing an electrochromic device, thereby solving the technical problems in the prior art where the electrochromic device has a yellowish background color, a high B value, and it is difficult to reduce the B value while simultaneously maintaining transmittance and electrochromic performance.

[0006] Another objective of the first aspect of the present invention is to further reduce the B value while improving the transmittance of the electrochromic device.

[0007] The second aspect of the present invention is to provide an electrochromic device prepared according to the above-described preparation method.

[0008] The third aspect of this invention aims to provide the application of electrochromic devices in electrochromic lenses.

[0009] According to a first aspect of the present invention, the present invention provides a method for preparing an electrochromic device, comprising the following steps: An electrochromic layer is deposited on the first transparent conductive layer. The electrochromic layer is made of tungsten oxide and has a thickness of any value between 200 nm and 260 nm. An ion-conducting layer is deposited on the electrochromic layer. The ion-conducting layer is made of tungsten oxide and has a thickness of any value between 160 nm and 200 nm. An ion storage layer is deposited on the ion conduction layer. The ion storage layer is made of nickel tungsten oxide and has a thickness of any value between 120 nm and 160 nm. Lithium-ion layer deposition is performed on the ion storage layer for a predetermined time. A second transparent conductive layer is deposited on the lithium-ion layer, and then subjected to a first annealing treatment and a second annealing treatment sequentially, so that lithium ions in the lithium-ion layer diffuse to the ion storage layer and reach a preset concentration; wherein, The annealing temperature of the first annealing process is lower than the annealing temperature of the second annealing process.

[0010] Optionally, the preset time is any value between 500s and 650s.

[0011] Optionally, the annealing temperature of the first annealing treatment is any value between 200℃ and 300℃, and the annealing temperature of the second annealing treatment is any value between 450℃ and 500℃.

[0012] Optionally, the annealing time for the first annealing process is any value between 400s and 600s, and the annealing time for the second annealing process is any value between 600s and 900s.

[0013] Optionally, the thickness of the first transparent conductive layer is any value between 250nm and 350nm.

[0014] Optionally, the thickness of the second transparent conductive layer is any value between 250nm and 350nm.

[0015] Optionally, the first and second transparent conductive layers are made of indium tin oxide or fluorine-doped tin oxide.

[0016] Optionally, the tungsten content in the ion storage layer is any value between 40% and 50%, and the nickel content is any value between 50% and 60%.

[0017] According to a second aspect of the present invention, the present invention also provides an electrochromic device prepared according to the preparation method of the electrochromic device according to any one of the preceding claims, the electrochromic device comprising a first transparent conductive layer, an electrochromic layer, an ion conducting layer, an ion storage layer and a second transparent conductive layer arranged sequentially from a substrate, wherein the background color B value of the electrochromic device is any value of 5-9 and the transmittance is any value of 80%-90%.

[0018] According to a third aspect of the present invention, the present invention also provides the application of the above-described electrochromic device in electrochromic lenses.

[0019] This invention achieves a significant reduction in the base color (B-value) of the electrochromic layer, ion-conducting layer, and ion-storage layer by thinning the electrochromic layer, synergistically adjusting the lithium-ion concentration to match the lithium-ion introduction amount with the film structure. This results in a substantial decrease in the yellowness of the electrochromic device, improving its overall color performance, while maintaining the electrochromic performance essentially unchanged. Furthermore, to address potential optical performance changes caused by the thinned structure, this embodiment introduces a two-step annealing process. The synergistic effect of low-temperature and high-temperature annealing regulates the defect state, valence state distribution, and ion intercalation state of the material, further reducing the B-value and optimizing transmittance. After the second annealing process, the electrochromic device maintains high transmittance while significantly improving the overall color tone, meeting the practical application requirements of electrochromic lenses and achieving a synergistic improvement in both overall color optimization and device optical performance.

[0020] Furthermore, the annealing temperature of the first annealing treatment in this invention is any value between 200℃ and 300℃, and the annealing temperature of the second annealing treatment is any value between 450℃ and 500℃. By limiting the first annealing and the second annealing to two different temperature zones of 200℃-300℃ and 450℃-500℃ respectively, the low-temperature defect control and high-temperature structural reconstruction form a synergistic effect, thereby further reducing the B value while improving the transmittance of the electrochromic device.

[0021] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0022] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic flowchart of a method for preparing an electrochromic device according to an embodiment of the present invention; Figure 2 This is a schematic structural diagram of an electrochromic device according to an embodiment of the present invention; Figure 3 This is a physical image of the electrochromic device according to Embodiment 1 of the present invention; Figure 4 This is a physical diagram of the electrochromic device according to Comparative Example 2 of the present invention; Figure 5 This is a physical diagram of the electrochromic device according to Comparative Example 5 of the present invention.

[0023] Figure label: 100 - Electrochromic device, 10 - First transparent conductive layer, 20 - Electrochromic layer, 30 - Ion conducting layer, 40 - Ion storage layer, 50 - Second transparent conductive layer. Detailed Implementation

[0024] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0025] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0026] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0027] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0028] Figure 1This is a schematic flowchart illustrating a method for fabricating an electrochromic device according to an embodiment of the present invention. Figure 2 This is a schematic structural diagram of an electrochromic device according to an embodiment of the present invention.

[0029] like Figure 1 As shown, the present invention provides an electrochromic device 100 (refer to...). Figure 2 The preparation method of ) includes the following steps: Step S100: Deposit an electrochromic layer 20 on the first transparent conductive layer 10. The electrochromic layer 20 is made of tungsten oxide and has a thickness of any value between 200nm and 260nm. That is, the thickness of the electrochromic layer 20 can be 200nm, 210nm, 220nm, 230nm or 260nm, or any other value between 200nm and 260nm. Step S200: Deposit an ion-conducting layer 30 on the electrochromic layer 20. The ion-conducting layer 30 is made of tungsten oxide and has a thickness of any value between 160nm and 200nm. That is, the thickness of the ion-conducting layer 30 can be 160nm, 170nm, 180nm, 190nm or 200nm, or any other value between 160nm and 200nm. Step S300: Deposit an ion storage layer 40 on the ion conduction layer 30. The ion storage layer 40 is made of nickel tungsten oxide and has a thickness of any value between 120nm and 160nm. The thickness of the ion storage layer 40 can be 120nm, 130nm, 140nm, 150nm, 155nm or 160nm, or any other value between 120nm and 160nm. Step S400: Deposit a lithium-ion layer on the ion storage layer 40 for a preset time; Step S500: Deposit a second transparent conductive layer 50 on the lithium ion layer, and perform a first annealing treatment and a second annealing treatment in sequence, so that the lithium ions in the lithium ion layer diffuse to the ion storage layer 40 and reach a preset concentration; wherein, the annealing temperature of the first annealing treatment is lower than the annealing temperature of the second annealing treatment.

[0030] In this embodiment, the fabrication method of the electrochromic device 100 includes the following steps: depositing an electrochromic layer 20 on a first transparent conductive layer 10, the electrochromic layer 20 being made of tungsten oxide with a thickness of 200nm-260nm; depositing an ion-conducting layer 30 on the electrochromic layer 20, the ion-conducting layer 30 being made of tungsten oxide with a thickness of 160nm-200nm; depositing an ion storage layer 40 on the ion-conducting layer 30, the ion storage layer 40 being made of nickel tungsten oxide with a thickness of 120nm-160nm; depositing a lithium-ion layer on the ion storage layer 40 for a preset time to control the amount of lithium ions introduced; subsequently depositing a second transparent conductive layer 50 on the lithium-ion layer, and performing a first annealing treatment and a second annealing treatment in sequence, wherein the temperature of the first annealing treatment is lower than the temperature of the second annealing treatment, the two-step annealing promotes the diffusion of lithium ions from the lithium-ion layer to the ion storage layer 40 and achieves stable embedding, thereby enabling the lithium ion concentration in the ion storage layer 40 to reach a preset target range.

[0031] In this embodiment, by thinning the electrochromic layer 20, ion-conducting layer 30, and ion-storage layer 40, and coordinating with lithium-ion concentration control, the amount of lithium-ion introduced is matched with the film structure. While ensuring the electrochromic performance remains essentially unchanged, the device's base color (B value) is effectively reduced, significantly lowering the yellowness of the electrochromic device 100 and improving its overall color performance. Furthermore, to address potential optical performance changes caused by the thinned structure, this embodiment introduces a two-step annealing process. Through the synergistic effect of low-temperature and high-temperature annealing, the defect state, valence state distribution, and ion intercalation state of the material are controlled, further reducing the B value and optimizing transmittance. After the second annealing treatment, the electrochromic device 100 maintains high transmittance while significantly improving the overall color tone, meeting the practical application requirements of electrochromic lenses, thus achieving a synergistic improvement between overall color optimization and device optical performance.

[0032] In this embodiment, by thinning the electrochromic layer 20, ion-conducting layer 30, and ion storage layer 40, the ineffective absorption regions in the thick film structure that do not participate in the electrochromic reaction are reduced, especially the portion of the ion storage layer 40 related to yellow absorption, thereby physically reducing the B-value of the device. Simultaneously, by shortening the deposition time of the lithium-ion layer, the amount of lithium-ion introduced is matched to the thickness of the thinned film, avoiding local enrichment and non-uniform distribution problems caused by excessive lithium-ion introduction. This further reduces the yellow component in the overall color while ensuring the effective conduction of the electrochromic reaction. The synergistic effect of the above-mentioned structural thinning and lithium-ion concentration regulation can achieve a decrease in the B-value without reducing the electrochromic performance; however, due to changes in the film structure and absorption characteristics, the transmittance will decrease to some extent.

[0033] Building upon this, a two-step annealing process was used to further regulate the material's structure and valence state. First, low-temperature annealing caused primary crystallization, followed by high-temperature secondary annealing for recrystallization. This ensured consistent crystal orientation and altered the valence state of the W layer in the ion storage layer 40, causing oxygen loss from a +6 valence state to a +5 valence state. This optimized the material's band structure and light absorption characteristics, further reducing the yellow absorption component and lowering the B value. Simultaneously, high-temperature annealing promoted lithium-ion diffusion and stable intercalation, improving its distribution uniformity and utilization efficiency, and to some extent, enhancing optical transmittance.

[0034] In a further embodiment, the preset time is any value between 500s and 650s, meaning the deposition time of the lithium-ion layer can be 500s, 570s, 580s, 590s, 600s, or 650s, or any other value between 500s and 650s. By controlling the deposition time of the lithium-ion layer within the range of 500s to 650s, under conventional deposition rate conditions in the art, the amount of lithium-ion introduced is effectively regulated, matching it with the thickness of the thinned ion storage layer 40. Controlling the deposition time within this range avoids the problems of insufficient electrochromic response due to excessively low lithium-ion introduction, or localized ion enrichment and additional light absorption due to excessively high introduction. This further reduces the B value of the electrochromic device 100 and optimizes the overall color performance while maintaining the basic electrochromic performance. Simultaneously, under subsequent secondary annealing, lithium ions can fully diffuse and uniformly embed into the ion storage layer 40, improving its utilization efficiency and allowing the electrochromic device 100 to maintain good optical performance while improving the overall color tone.

[0035] In this embodiment, the deposition of the lithium-ion layer is carried out using a conventional physical vapor deposition process. Its deposition rate is affected by a variety of process parameters such as radio frequency power, target oscillation amplitude, and gas pressure, making it difficult to precisely quantify a single variable. This application does not limit the deposition rate and thickness of the lithium-ion layer, but rather adjusts the amount of lithium ions introduced by controlling the deposition time.

[0036] In a further embodiment, the annealing temperature for the primary annealing process is any value between 200℃ and 300℃, and the annealing temperature for the secondary annealing process is any value between 450℃ and 500℃. That is, the temperature for the primary annealing process can be 200℃, 220℃, 240℃, 260℃, 280℃, or 300℃, or any other value between 200℃ and 300℃. The temperature for the secondary annealing process can be 450℃, 460℃, 470℃, 480℃, 490℃, or 500℃, or any other value between 450℃ and 500℃. By limiting the primary and secondary annealing processes to two different temperature ranges, 200℃-300℃ and 450℃-500℃ respectively, a synergistic effect is achieved between low-temperature defect control and high-temperature structural reconstruction, thereby further reducing the B-value while improving the transmittance of the electrochromic device 100.

[0037] Specifically, by controlling the primary annealing temperature within the range of 200℃-300℃, the film is subjected to low-temperature treatment under relatively oxygen-rich conditions. This helps to regulate the oxygen content and defect state in the material, suppress non-selective absorption caused by oxygen vacancies, and shift the overall color from a yellowish hue to a bluish-green. Simultaneously, it improves the interfacial bonding between functional layers and alleviates internal stress, providing a stable foundation for subsequent structural reconstruction. Furthermore, by controlling the secondary annealing temperature within the range of 450℃-500℃, the material undergoes valence state regulation and structural rearrangement under relatively oxygen-depleted and high-temperature conditions. This promotes high-temperature recrystallization, thereby optimizing the band structure and weakening the yellow absorption component, further reducing the B value.

[0038] Furthermore, high-temperature annealing can promote the diffusion and stable embedding of lithium ions from the surface layer into the ion storage layer 40, making the distribution of lithium ions in the film layer more uniform and improving its utilization efficiency. While ensuring that the electrochromic performance remains essentially unchanged, the transmittance of the device is optimized to a certain extent. Thus, through the division of labor and synergy between low-temperature and high-temperature annealing in different temperature zones, a comprehensive effect of defect control, valence state control, and ion distribution optimization is achieved. This allows the device to maintain good optical performance while significantly improving the overall color, thereby achieving synergistic optimization of overall color tone and device performance.

[0039] In a further embodiment, the annealing time for the primary annealing process is any value between 400s and 600s, and the annealing time for the secondary annealing process is any value between 600s and 900s. That is, the annealing time for the primary annealing process can be 400s, 420s, 440s, 500s, 550s, or 600s, or any other value between 400s and 600s; the annealing time for the secondary annealing process can be 600s, 650s, 680s, 700s, 800s, or 900s, or any other value between 600s and 900s. By controlling the annealing times of both the primary and secondary annealing processes within the range of 600s to 900s, both the low-temperature and high-temperature annealing processes have sufficient and appropriate action time, thereby ensuring the full realization of the control effects at each stage. Specifically, in the first annealing stage, the low-temperature treatment time of 600s-700s is conducive to the stable control of oxygen content and defect state in the material, effectively regulating defects such as oxygen vacancies, thereby suppressing non-selective light absorption and improving the overall color performance. At the same time, it releases the interfacial stress between functional layers and enhances the interlayer bonding stability.

[0040] Furthermore, in the secondary annealing stage, a high-temperature treatment time of 600-700 seconds promotes the internal structural rearrangement and high-temperature recrystallization process of the material, stabilizing the valence state distribution and further weakening the yellow absorption component and reducing the B value. Simultaneously, this time range effectively promotes the diffusion and uniform embedding of lithium ions from the surface layer into the ion storage layer 40, improving lithium ion utilization efficiency and avoiding local enrichment due to insufficient diffusion or structural degradation caused by over-annealing. Therefore, through reasonable control of the two-step annealing time, defect regulation, structural reconstruction, and lithium ion distribution optimization processes can be fully and synergistically carried out, reducing the B value, improving the overall color, and maintaining good electrochromic performance of the device.

[0041] In a further embodiment, the thickness of the first transparent conductive layer 10 is any value between 250nm and 350nm. The thickness of the first transparent conductive layer 10 can be 250nm, 260nm, 270nm, 280nm, 290nm, or 350nm, or any other value within the 250nm-350nm range. In this embodiment, by controlling the thickness of the first transparent conductive layer 10 within the range of 250nm-350nm, it achieves both good conductivity and high optical transmittance. When the thickness is within this range, the transparent conductive layer can form a continuous and dense conductive network, thereby reducing sheet resistance and ensuring uniform current distribution during device driving, which is beneficial for the stable conduction of the electrochromic reaction. Simultaneously, this thickness range can effectively control absorption and reflection losses in the visible light region, avoiding problems such as decreased transmittance due to excessive film thickness or insufficient conductivity due to excessively thin film. Furthermore, the thickness range can also form a good optical matching relationship with the upper electrochromic functional structure, optimize the light interference effect in the multilayer film structure, and improve the overall light transmittance and comprehensive color performance of the device while ensuring conductivity and structural stability, thereby realizing the synergistic support of the transparent conductive layer for the optical performance and electrochromic performance of the device.

[0042] In a further embodiment, the thickness of the second transparent conductive layer 50 is any value between 250nm and 350nm, that is, the thickness of the second transparent conductive layer 50 can be 250nm, 260nm, 270nm, 280nm, 290nm, or 350nm, or any other value between 250nm and 350nm. By controlling the thickness of the second transparent conductive layer 50 within the range of 250nm-350nm, it can simultaneously serve as the upper electrode and possess good conductivity and optical transmittance. Specifically, when the thickness is within this range, the second transparent conductive layer 50 can form a continuous and dense conductive film layer, thereby reducing sheet resistance and ensuring the uniformity of the electric field distribution of the electrochromic device 100 during operation, which is beneficial to the synchronicity and stability of the electrochromic reaction. At the same time, this thickness range can effectively reduce absorption and reflection losses in the visible light region, avoiding problems such as decreased transmittance due to excessively thick film layers or insufficient conductivity and film discontinuity due to excessively thin film layers.

[0043] Furthermore, the second transparent conductive layer 50 serves as the light incident or emitting interface, and its thickness allows it to form a good optical matching relationship with the underlying electrochromic functional structure and the first transparent conductive layer 10. This enables the modulation of interference effects in the multilayer film structure, optimizing the overall light transmittance of the device and improving its overall color performance to a certain extent. In addition, this thickness range also helps to enhance the encapsulation protection of the internal functional layers, thereby improving the structural stability and environmental tolerance of the device.

[0044] In a further embodiment, the first transparent conductive layer 10 and the second transparent conductive layer 50 are made of indium tin oxide (ITO) or fluorine-doped tin oxide. In this embodiment, the selection of ITO or fluorine-doped tin oxide as the materials for the first transparent conductive layer 10 and the second transparent conductive layer 50 allows them to possess both excellent conductivity and optical transmittance. Specifically, ITO and fluorine-doped tin oxide, as typical transparent conductive oxides, have low sheet resistance and high visible light transmittance, which helps to reduce the driving voltage of the electrochromic device 100 and ensure the uniformity of the electric field distribution during the electrochromic process, thereby improving the stability and response consistency of the electrochromic reaction.

[0045] Meanwhile, the aforementioned materials exhibit low absorption loss in the visible light range, which helps reduce the overall light loss of the electrochromic device 100. Combined with structural layer thinning and lithium-ion modulation, this further enhances the light transmittance of the electrochromic device 100 and improves its overall color performance. Furthermore, indium tin oxide and fluorine-doped tin oxide have good interfacial compatibility with the electrochromic layer 20 and the ion-functional layer, and are less prone to interfacial degradation during subsequent annealing, which helps maintain the stability of the film structure and promotes the effective transport and stable intercalation of lithium ions.

[0046] In a further embodiment, the tungsten content in the ion storage layer 40 is any value between 40% and 50%, and the nickel content is any value between 50% and 60%. Specifically, the tungsten content in the ion storage layer 40 can be 40%, 42%, 44%, 46%, 48%, or 50%, or any other value between 40% and 50%. The nickel content can be 50%, 52%, 54%, 56%, 58%, or 60%, or any other value between 50% and 60%. By precisely controlling the tungsten and nickel content within the aforementioned ranges, the ion storage layer 40 exhibits excellent comprehensive performance while possessing good ion storage capabilities. Specifically, within this content range, tungsten and nickel can form a stable and suitable alloy structure. This structure provides abundant storage sites for ions, facilitating ion insertion and extraction, thereby ensuring the efficient ion storage capacity of the ion storage layer 40 and meeting the ion storage and release requirements of the electrochromic device 100 during operation. Meanwhile, this alloy structure can effectively reduce the resistance to ion transport within the layer, accelerate ion migration rate, and enable the electrochromic reaction to respond rapidly, thereby improving the dynamic performance of the device. In addition, an appropriate tungsten-nickel content ratio can optimize the optical performance of the ion storage layer 40, reduce the absorption and scattering of visible light, and avoid problems such as reduced transmittance or optical inhomogeneity caused by improper element content, ensuring that the electrochromic device 100 maintains good optical quality during the color-changing process.

[0047] This invention also provides an electrochromic device 100 prepared according to the above-described method for preparing an electrochromic device 100. The electrochromic device 100 includes a first transparent conductive layer 10, an electrochromic layer 20, an ion-conducting layer 30, an ion-storage layer 40, and a second transparent conductive layer 50, which are sequentially stacked from the substrate. The background color B value of the electrochromic device 100 is any value between 5 and 9, and the transmittance is any value between 80% and 90%. In this embodiment, the electrochromic device 100 prepared by the above-described method adopts a stacked structure of the first transparent conductive layer 10, the electrochromic layer 20, the ion-conducting layer 30, the ion-storage layer 40, and the second transparent conductive layer 50. Combined with thinning design, lithium-ion concentration control, and two-step annealing treatment, the synergistic optimization of the overall color tone and optical performance of the device is achieved. Specifically, by rationally controlling the thickness of the functional layer and precisely adjusting the amount of lithium ions introduced, the yellow component of the device is effectively reduced, the B value of the background color is controlled within the range of 5-9, and the overall color is closer to neutral gray or slightly cool tone, thereby significantly improving the visual effect.

[0048] Furthermore, by controlling the material defect state, valence state distribution, and lithium-ion intercalation state during the annealing process, a high optical transmittance is maintained while reducing the B value, ensuring that the device transmittance remains above 80%, meeting the application requirements of electrochromic lenses for light transmission. In addition, due to the good interface matching relationship formed between the first transparent conductive layer 10, the electrochromic layer 20, the ion conducting layer 30, the ion storage layer 40, and the second transparent conductive layer 50, the electrochromic device 100 achieves comprehensive color optimization while maintaining stable electrochromic performance and good recyclability.

[0049] The present invention also provides the application of the above-described electrochromic device 100 in electrochromic lenses.

[0050] The technical solution of this application will be further described below with reference to specific embodiments.

[0051] In some embodiments, step S100: depositing an electrochromic layer 20 on the first transparent conductive layer 10, wherein the electrochromic layer 20 is made of tungsten oxide and has a thickness of any value between 200nm and 260nm. Step S200: Deposit an ion-conducting layer 30 on the electrochromic layer 20. The ion-conducting layer 30 is made of tungsten oxide and has a thickness of any value between 160nm and 200nm. Step S300: Deposit an ion storage layer 40 on the ion conduction layer 30. The ion storage layer 40 is made of nickel tungsten oxide and has a thickness of any value between 120nm and 160nm. Step S400: Deposit a lithium-ion layer on the ion storage layer 40 for a preset time, the preset time being any value between 500s and 650s. Step S500: Deposit a second transparent conductive layer 50 on the lithium-ion layer, and perform a first annealing treatment and a second annealing treatment in sequence to allow lithium ions in the lithium-ion layer to diffuse to the ion storage layer 40 and reach a preset concentration; wherein, the annealing temperature of the first annealing treatment is any value between 200℃ and 300℃, the annealing temperature of the second annealing treatment is any value between 450℃ and 500℃, the annealing time of the first annealing treatment is any value between 400s and 600s, and the annealing time of the second annealing treatment is any value between 600s and 900s.

[0052] Example 1 Step S100: Deposit an electrochromic layer 20 on the first transparent conductive layer 10. The electrochromic layer 20 is made of tungsten oxide and has a thickness of 230 nm. Step S200: Deposit an ion-conducting layer 30 on the electrochromic layer 20. The ion-conducting layer 30 is made of tungsten oxide and has a thickness of 160 nm. Step S300: Deposit an ion storage layer 40 on the ion conduction layer 30. The ion storage layer 40 is made of nickel tungsten oxide and has a thickness of 140 nm. Step S400: Deposit a lithium-ion layer on the ion storage layer 40 for a preset time, the preset time being 600s; Step S500: Deposit a second transparent conductive layer 50 on the lithium-ion layer, and perform a first annealing treatment and a second annealing treatment in sequence to allow lithium ions in the lithium-ion layer to diffuse to the ion storage layer 40 and reach a preset concentration; wherein, the annealing temperature of the first annealing treatment is 250℃, the annealing temperature of the second annealing treatment is 475℃, the annealing time of the first annealing treatment is 480s, and the annealing time of the second annealing treatment is 800s.

[0053] Example 2 The only difference between Example 2 and Example 1 is that the thickness of the electrochromic layer 20 is 240 nm, the thickness of the ion conduction layer 30 is 180 nm, the thickness of the ion storage layer 40 is 150 nm, and the deposition time of the lithium ion layer is 620 s.

[0054] Example 3 The only difference between Example 3 and Example 1 is that the thickness of the electrochromic layer 20 is 260 nm, the thickness of the ion conduction layer 30 is 190 nm, the thickness of the ion storage layer 40 is 160 nm, and the deposition time of the lithium ion layer is 650 s.

[0055] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that after depositing the second transparent conductive layer 50, only one annealing treatment is performed, and the annealing temperature is 450°C.

[0056] Comparative Example 2 The only difference between Comparative Example 2 and Example 1 is that after depositing the second transparent conductive layer 50, only one annealing treatment was performed, and the annealing temperature was 480°C.

[0057] Comparative Example 3 The only difference between Comparative Example 3 and Example 1 is that the lithium ion layer deposition time is 660s.

[0058] Comparative Example 4 The only difference between Comparative Example 4 and Example 1 is that the lithium ion layer deposition time is 680s.

[0059] Comparative Example 5 The only difference between Comparative Example 5 and Example 1 is that the thickness of the electrochromic layer 20 is 330 nm.

[0060] Comparative Example 6 The only difference between Comparative Example 6 and Example 1 is that the thickness of the ion-conducting layer 30 is 220 nm.

[0061] Comparative Example 7 The only difference between Comparative Example 7 and Example 1 is that the thickness of the ion storage layer 40 is 200 nm.

[0062] Comparative Example 8 The only difference between Comparative Example 8 and Example 1 is that the electrochromic layer 20 has a thickness of 330 nm, the ion conduction layer 30 has a thickness of 220 nm, and the ion storage layer 40 has a thickness of 200 nm.

[0063] Figure 3 This is a physical image of the electrochromic device according to Embodiment 1 of the present invention. Figure 4 This is a physical diagram of the electrochromic device according to Comparative Example 2 of the present invention. Figure 5 This is a physical diagram of the electrochromic device according to Comparative Example 5 of the present invention.

[0064] Sheet resistance, transmittance, performance, and cycle stability tests were performed on the electrochromic devices 100 in Examples 1-3 and Comparative Examples 1-8, respectively, and the results are shown in Table 1 and... Figures 3 to 5 The test results are shown.

[0065]

[0066] As shown in Table 1 and Figures 3 to 5 As shown, the electrochromic device 100 in Examples 1-3 effectively reduces the base color B value while maintaining its basic electrochromic performance. The B value in Example 1 is 7, and the yellowness of the electrochromic device 100 is significantly reduced (refer to...). Figure 3The B value of Example 2 was 8, and the B value of Example 3 was 9, both significantly lower than the background B value of each electrochromic device 100 in Comparative Examples 1-8. That is, the background yellowness of the electrochromic devices 100 in Comparative Examples 2 and 5 was significantly higher than that in Example 1 (refer to Example 1). Figure 4 and Figure 5 This indicates that the synergistic effect of thinning treatment and lithium-ion concentration regulation effectively improves the overall color performance of the electrochromic device 100, reduces the influence of yellow tint on the overall color, and makes the electrochromic device 100 present a more ideal color.

[0067] Furthermore, to address the potential changes in optical performance caused by thinning, this application introduces a two-step annealing process. Through the synergistic effect of low-temperature and high-temperature annealing, the defect state, valence state distribution, and ion intercalation state of the material are precisely controlled. Transmittance test results show that the transmittance of Examples 1-3 is significantly higher than that of the comparative examples. Example 1 has a transmittance of 85%, Example 2 has 88%, and Example 3 reaches 90%; while Comparative Example 1 has 82% and Comparative Example 3 has 80%. This indicates that the two-step annealing process further optimizes transmittance, enabling the electrochromic device to maintain high transmittance while significantly improving the overall color tone, thus meeting the optical performance requirements of practical applications such as electrochromic lenses.

[0068] Meanwhile, comparing Examples 1-3 with Comparative Examples 5-8 reveals that when the thicknesses of the electrochromic layer 20, the ion-conducting layer 30, and the ion-storage layer 40 exceed the ranges set in this application—for example, in Comparative Examples 5-8, when the thickness of the electrochromic layer is 330 nm, the ion-conducting layer is 220 nm, and the ion-storage layer is 200 nm—the B-value increases significantly, the transmittance decreases, and the color-changing performance is also affected to some extent. Furthermore, comparing Examples 1 with Comparative Examples 3-4 shows that excessively long lithium-ion layer deposition times lead to an increase in the B-value and a decrease in transmittance, indicating that both the lithium-ion deposition time and the thickness of each film layer in the electrochromic device 100 must be within the ranges set in this application to maintain the good optical and color-changing performance of the electrochromic device 100.

[0069] Finally, a significant difference exists in the performance of electrochromic devices between single-step and two-step annealing processes. Comparing Example 1 with Comparative Examples 1-2, it is evident that the device undergoing only single-step annealing (450℃ in Comparative Example 1, 480℃ in Comparative Example 2) has a higher base color B value than Example 1 (13 in Comparative Example 1, 11 in Comparative Example 2, 7 in Example 1), and its transmittance is also relatively lower (82% in Comparative Example 1, 83% in Comparative Example 2, 85% in Example 1). These results indicate that the two-step annealing process has significant advantages in reducing the B value and optimizing transmittance, achieving a synergistic improvement in both overall color optimization and device optical performance.

[0070] In summary, this invention effectively reduces the base color B value of the electrochromic device 100 by thinning the electrochromic layer 20, the ion conduction layer 30, and the ion storage layer 40 and precisely controlling the lithium ion concentration, combined with a two-step independent annealing process. This reduces the yellowness and optimizes the overall color performance, while significantly improving the transmittance. Furthermore, it exhibits excellent color-changing performance and good cycle stability.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing an electrochromic device, characterized in that, Includes the following steps: An electrochromic layer is deposited on the first transparent conductive layer. The electrochromic layer is made of tungsten oxide and has a thickness of any value between 200 nm and 260 nm. An ion-conducting layer is deposited on the electrochromic layer. The ion-conducting layer is made of tungsten oxide and has a thickness of any value between 160 nm and 190 nm. An ion storage layer is deposited on the ion conduction layer. The ion storage layer is made of nickel tungsten oxide and has a thickness of any value between 120 nm and 160 nm. Lithium-ion layer deposition is performed on the ion storage layer for a preset time, wherein the preset time is any value between 500s and 650s. A second transparent conductive layer is deposited on the lithium-ion layer, and then subjected to a first annealing treatment and a second annealing treatment sequentially, so that lithium ions in the lithium-ion layer diffuse to the ion storage layer and reach a preset concentration; wherein, The annealing temperature of the first annealing process is lower than the annealing temperature of the second annealing process; The annealing temperature for the first annealing process is any value between 200℃ and 300℃, and the annealing temperature for the second annealing process is any value between 450℃ and 500℃. The annealing time for the first annealing process is any value between 400s and 600s, and the annealing time for the second annealing process is any value between 600s and 900s.

2. The method for preparing the electrochromic device according to claim 1, characterized in that, The thickness of the first transparent conductive layer is any value between 250nm and 350nm.

3. The method for preparing the electrochromic device according to claim 1, characterized in that, The thickness of the second transparent conductive layer is any value between 250nm and 350nm.

4. The method for preparing the electrochromic device according to any one of claims 1-3, characterized in that, The first and second transparent conductive layers are made of indium tin oxide or fluorine-doped tin oxide.

5. The method for preparing the electrochromic device according to claim 4, characterized in that, The ion storage layer contains tungsten of any value between 40% and 50%, and nickel of any value between 50% and 60%.

6. An electrochromic device prepared by the method according to any one of claims 1-5, characterized in that, The electrochromic device comprises a first transparent conductive layer, an electrochromic layer, an ion-conducting layer, an ion-storage layer, and a second transparent conductive layer, which are stacked sequentially from the substrate to the top. The background color B value of the electrochromic device is any value between 5 and 9, and the transmittance is any value between 80% and 90%.

7. The application of the electrochromic device according to claim 6 in electrochromic lenses.

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