Structure of and preparation method for electrochromic device including reference electrode

Abstract

Disclosed in the present application are a structure of and preparation method for an electrochromic device including a reference electrode. The structure comprises: at least one reference electrode, and a first conductive substrate layer, an electrochromic layer, an electrolyte layer, an ion storage layer and a second conductive substrate layer, which are stacked from bottom to top, wherein the reference electrode is arranged on the side of the electrolyte layer close to the electrochromic layer or on the side of the electrolyte layer close to the ion storage layer; the reference electrode is in contact with the electrolyte layer and does not participate in the reaction of the electrochromic layer, and is used for providing a potential reference; and when two reference electrodes are introduced, one of the reference electrodes can serve as a third electrode to form a voltage loop with the first conductive substrate layer, and the other forms a voltage loop with any one of the other three electrodes. The technical solution of the present application can monitor voltage and current changes of the electrochromic layer and ion storage layer in the electrochromic device to realize in-situ electrochromic spectrum research, and can precisely control the potential of the electrochromic layer on the basis of the potential reference, thereby improving the electrochemical and spectral repeatability of the device.

Description

Structure and fabrication method of electrochromic device including reference electrode

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 202411441486.2, filed on October 15, 2024, entitled "Structure and Fabrication Method of Electrochromic Device Including Reference Electrode". Technical Field

[0003] This application relates to the technical fields of electrochromism and electrochemistry, and more specifically, to an electrochromic device structure and preparation method including a reference electrode. Background Technology

[0004] Electrochromic devices are a type of device whose apparent color changes under the influence of different external electric fields, meaning that their spectral state (transmittance or reflectance) is controlled by the electric field.

[0005] Currently, the electrochemical spectra of electrochromic materials reported in the literature are all measured using a three-electrode system in an electrochemical cell. However, the packaging of electrochromic devices generally employs a simple two-electrode configuration, and only the potential step method is used to control the coloring and fading of the electrochromic device. Compared to the three-electrode system, the counter electrode in the two-electrode system acts as both the polarization electrode and the reference electrode, making the measured electrode potential more susceptible to the influence of the polarization current. Furthermore, for conductive polymer electrochromic materials, numerous reports indicate that their conductivity varies significantly under different doping states. This means that in a two-electrode system, with different degrees of redox, the conductive polymer film continuously changes the ohmic polarization of the device, and the voltage division of the film will change with the external voltage, resulting in inconsistencies between the measured and applied voltages, thus affecting the precise electrochemical control of such devices.

[0006] In the study of using electrochromic devices as spectral modulation elements, reliable optical control is required, which means that the thin film potential must be more precise. Summary of the Invention

[0007] The purpose of this application is to solve the problems in the prior art that electrochromic materials cannot be measured in situ and that existing electrochromic devices cannot be accurately electrochemically controlled due to polarization. The application provides an electrochromic device that can be measured in situ. A reference electrode is introduced into the electrochromic device to provide an accurate potential reference for the electrochromic layer, thereby enabling in-situ electrochromic spectral research and potential matching analysis during the electrochromic process.

[0008] The technical solution of this application is: to provide an electrochromic device structure including a reference electrode, comprising at least one reference electrode, and a first conductive substrate layer, an electrochromic layer, an electrolyte layer, an ion storage layer and a second conductive substrate layer stacked from bottom to top;

[0009] The reference electrode is disposed in the electrolyte layer on the side close to the electrochromic layer, and an isolation is provided between the reference electrode and the electrochromic layer; or, the reference electrode is disposed in the electrolyte layer on the side close to the ion storage layer, and an isolation is provided between the reference electrode and the ion storage layer.

[0010] The reference electrode is in contact with the electrolyte layer and is used to provide a potential reference for the electrochromic layer.

[0011] Furthermore, the electrochromic device structure also includes a working electrode connection layer and a counter electrode connection layer;

[0012] The first conductive substrate layer and the second conductive substrate layer are laterally displaced. The electrochromic layer is disposed above the first conductive substrate layer and in the area where the first conductive substrate layer and the second conductive substrate layer overlap each other. The working electrode connection layer is disposed in the area on the first conductive substrate layer that extends laterally relative to the second conductive substrate layer.

[0013] An ion storage layer is disposed below the second conductive substrate layer and in the region where the first conductive substrate layer and the second conductive substrate layer overlap each other, and an electrode connection layer is disposed on the second conductive substrate layer in a region that extends laterally relative to the first conductive substrate layer.

[0014] Furthermore, the reference electrode includes an insulating flexible substrate and an electrode material, the electrode material being coated on the insulating flexible substrate, and the material of the reference electrode being selected from Ag or AgCl; the material of the insulating flexible substrate is selected from polyethylene terephthalate, polyimide, polypropylene, polystyrene, or polydimethylsiloxane.

[0015] The electrochromic layer is made of a conductive polymer electrochromic material, which is a polymer or copolymer of one or more materials selected from the group consisting of: aniline, pyrrole, thiophene, 3-hexylthiophene, 3,4-ethylenedioxythiophene, o-phenylenediamine, m-phenylenediamine, o-toluidine, o-methoxyaniline, o-aminobenzenesulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid, and thiophene[3,4-B]-1,4-dioxin-2-methanol.

[0016] The technical solution of this application also provides a method for fabricating an electrochromic device including a reference electrode, comprising:

[0017] Step 1: Prepare a reference electrode of the predetermined size;

[0018] Step 2: Coat an electrochromic layer material on the first conductive substrate layer, and after it has cured, remove a predetermined width of the electrochromic layer material from one side edge, and set a working electrode connection layer at the location where the material was removed.

[0019] Step 3: Attach the reference electrode to the electrochromic layer using insulating double-sided adhesive tape, wherein the area of ​​the insulating double-sided adhesive tape is larger than the area of ​​the reference electrode on the side closest to the electrochromic layer.

[0020] Step 4: Coat the second conductive substrate with ion storage layer material, and after it has cured, remove the ion storage layer material of a predetermined width from one side edge, and set the counter electrode connection layer at the location where the material was removed.

[0021] Step 5: Bond the electrochromic layer and the ion storage layer together, and place an electrolyte layer between the electrochromic layer and the ion storage layer;

[0022] Step 6: Seal the edges of the electrochromic device.

[0023] Further, step 1 includes: coating a reference electrode material onto a prepared substrate, performing a heat annealing treatment, and cutting it to a predetermined size after it has solidified to obtain a reference electrode.

[0024] Furthermore, step 5 includes:

[0025] The electrochromic layer is bonded to the ion storage layer using adhesive. A cavity is created in the central area of ​​the adhesive, and liquid electrolyte is injected into the cavity, allowing the reference electrode to come into direct contact with the liquid electrolyte.

[0026] Alternatively, a gel electrolyte can be coated onto an ion storage layer, and the ion storage layer and an electrochromic layer film can be bonded together so that the reference electrode is in direct contact with the gel electrolyte.

[0027] The technical solution of this application also provides an application of an electrochromic device in voltage and current measurement and control, wherein the positive and negative terminals of an external source meter are connected to the working electrode connection layer and the counter electrode connection layer respectively to supply power to the electrochromic device, the working electrode connection layer and the counter electrode connection layer are connected to an ammeter respectively to form a current loop, and the working electrode connection layer and the reference electrode are connected to a voltmeter respectively to form a voltage loop.

[0028] When controlling the voltage of an electrochromic device, the relative potential between the working electrode connection layer and the reference electrode is observed by a voltmeter. Based on the observation results, the relative potential is precisely adjusted to the target value by a source meter.

[0029] When controlling the current of an electrochromic device, the current between the working electrode connection layer and the counter electrode connection layer is observed by an ammeter. Based on the observation results, the current magnitude is precisely adjusted by the source meter.

[0030] The technical solution of this application also provides an application of an electrochromic device in electrochromic spectroscopy research, wherein the positive and negative electrodes of the source meter are connected to the working electrode connection layer and the counter electrode connection layer respectively to supply power to the electrochromic device, the working electrode connection layer is used as the first electrode, the counter electrode connection layer is used as the second electrode, and the reference electrode close to the electrochromic layer is used as the third electrode. The first electrode and the third electrode are connected to a voltmeter respectively to form a voltage loop, wherein the source meter is used to supply power;

[0031] Using the potential of the third electrode as a reference, the potential of the first electrode is adjusted to different target potentials through the source table. The spectral response of the electrochromic layer corresponding to different target potentials is obtained, and the spectral characteristics of the electrochromic layer at different target potentials are recorded to form a database for spectral research.

[0032] The technical solution of this application also provides an application of an electrochromic device in potential matching analysis, wherein the electrochromic device includes two reference electrodes, one of which is close to the electrochromic layer and the other is close to the ion storage layer, the working electrode connection layer is used as the first electrode, the counter electrode connection layer is used as the second electrode, the reference electrode close to the electrochromic layer is used as the third electrode, and the reference electrode close to the ion storage layer is used as the fourth electrode.

[0033] When measuring the potential change of the electrochromic layer, the positive and negative terminals of the first source meter are connected to the first and third electrodes respectively to supply power to the electrochromic device. The first and third electrodes are connected to the voltmeter to form the first voltage loop. The first source meter is used to repeatedly scan within the set potential range to record the first potential change curve between the first and third electrodes.

[0034] When measuring the potential change of the ion storage layer, the positive and negative terminals of the second source meter are connected to the fourth and second electrodes respectively to supply power to the electrochromic device. The fourth and second electrodes are connected to the voltmeter to form a second voltage loop. The second source meter is used to repeatedly scan within the set potential range to record the second potential change curve between the fourth and second electrodes.

[0035] Based on the first and second potential change curves, the potential matching between the electrochromic layer and the ion storage layer is calculated. Materials for fabricating the electrochromic layer and the ion storage layer are then selected based on the potential matching between the two layers. The specific steps include the following:

[0036] S301: Select one material from each of the two groups of candidate materials to serve as the electrochromic layer and the ion storage layer, respectively, and fabricate an electrochromic device;

[0037] S302: The first potential change curve of the electrochromic layer is obtained by repeatedly scanning within the set potential range using the first source meter. At the same time, the second potential change curve of the ion storage layer is obtained by monitoring the potential using the second source meter.

[0038] S303: Within the set potential range, observe whether the change directions of the first potential change curve and the second potential change curve are opposite. If they are not opposite, it is determined that the potentials of the electrochromic layer and the ion storage layer are mismatched. If they are opposite, the second potential change curve is reversed in the vertical direction. The two points corresponding to the horizontal coordinates in the first potential change curve and the reversed second potential change curve are taken as a set of comparison points. The average distance between the comparison points is calculated. When the average distance is greater than the preset threshold, it is determined that the potentials of the electrochromic layer and the ion storage layer are mismatched. When the average distance is less than or equal to the preset threshold, it is determined that the potentials of the electrochromic layer and the ion storage layer are matched.

[0039] The materials used in the potential-matched electrochromic layer and ion storage layer, as well as the corresponding potential ranges, are recorded.

[0040] S304: Update the set potential range, rescan the electrochromic layer and ion storage layer where the potentials do not match, obtain the updated first potential change curve and second potential change curve, and determine whether the potentials of the electrochromic layer and ion storage layer match according to the method in S303. When the potentials of the electrochromic layer and ion storage layer match, record the currently used material and the corresponding potential range. When the potentials of the electrochromic layer and ion storage layer match, continue to update the set potential range and perform potential matching judgment until the preset number of iterations is reached.

[0041] The technical solution of this application also provides a patterned electrochromic device prepared by a method for preparing an electrochromic device including a reference electrode, comprising at least one reference electrode and one or more electrochromic layers distributed according to a predetermined pattern, wherein the reference electrode is a common electrode for the region where all electrochromic layers are located, and is used to provide a uniform potential reference for the region where all electrochromic layers are located.

[0042] The beneficial effects of this application are:

[0043] First, the technical solution in this application provides a low-cost, easy-to-manufacture device structure and preparation method including a reference electrode. By introducing one or more reference electrodes into the electrochromic device, the reference electrodes do not participate in the electrochromic reaction and can provide a stable potential reference for the electrochromic layer. By comparing the potential between the reference electrode and the working electrode, the voltage applied to the working electrode can be precisely controlled, while avoiding measurement errors caused by electrode potential drift. Compared with existing devices, the technical solution in this application can eliminate the voltage deviation caused by the ohmic polarization of the electropolymer electrochromic material through the reference electrode, improve the accuracy and stability of electrochemical control, and thus improve the electrochemical repeatability and spectral repeatability of the device.

[0044] Secondly, the technical solution in this application can be better applied to electrochromic spectroscopy research. By using the electrochromic device as a general-purpose spectral control element, and controlling the potential difference between the reference electrode and the working electrode, the potential on the working electrode can be more accurately adjusted to the target potential, and the spectral characteristics of the electrochromic layer under different target potentials can be accurately obtained. This avoids the problem of inaccurate spectral characteristic analysis caused by the inability to accurately measure the working electrode potential. The technical solution in this application can non-destructively monitor the voltage and current changes of the electrochromic layer in the electrochromic device, and realize in-situ spectral research of the electrochromic device.

[0045] Third, the technical solution in this application can be applied to potential matching analysis in the electrochromic process. Reference electrodes are set near the electrochromic layer and near the ion storage layer, respectively. By using different reference electrodes, the potential changes of the working electrode and the counter electrode can be accurately measured to help analyze the potential matching between the electrochromic layer and the ion storage layer. Based on the potential matching between the electrochromic layer and the ion storage layer, more suitable materials for fabricating the electrochromic layer and the ion storage layer can be selected. Compared with existing devices, the technical solution in this application can realize in-situ measurement of the device, improving the accuracy of the measurement results. Attached Figure Description

[0046] The advantages of the above and / or additional aspects of this application will become apparent and readily understood in the description of the embodiments in conjunction with the following drawings, wherein:

[0047] Figure 1 is a schematic diagram of the structure of an electrochromic device including a reference electrode according to an embodiment of this application;

[0048] Figure 2 shows the CV curve and the corresponding electrochromic spectrum of the three-electrode electrochromic device prepared in Example 1.

[0049] Figure 3 shows the CV curve and corresponding electrochromic spectrum of an existing two-electrode electrochromic device.

[0050] Figure 4 shows the CV curve of the three-electrode electrochromic device prepared in Example 2 and the electrochromic spectrum of the device under different test cycles.

[0051] Figure 5 shows the test circuit diagram of the three-electrode electrochromic device prepared in Example 1 and the voltage change of the entire device during the corresponding CV cycle.

[0052] Figure 6 shows the potential changes of different ion storage layers in the four-electrode electrochromic device prepared in Example 3.

[0053] Figure 7 is a schematic diagram and a physical image of the packaged three-electrode device prepared in Example 1;

[0054] Figure 8 is a physical image of the packaged four-electrode device prepared in Example 3.

[0055] Among them, 1-first conductive substrate layer, 11-conductive material ITO, 2-electrochromic layer, 3-electrolyte layer, 4-ion storage layer, 5-second conductive substrate layer, 6-reference electrode, 7-working electrode connection layer, 8-working electrode connection layer, and 9-encapsulating adhesive. Detailed Implementation

[0056] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

[0057] In the following description, many specific details are set forth in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0058] As shown in Figure 1, this embodiment provides an electrochromic device structure including a reference electrode, comprising at least one reference electrode 6, and a first conductive substrate layer 1, an electrochromic layer 2, an electrolyte layer 3, an ion storage layer 4, and a second conductive substrate layer 5 stacked from bottom to top.

[0059] The reference electrode 6 is disposed in the electrolyte layer 3 on the side close to the electrochromic layer 2 and is isolated from the electrochromic layer 2; or, the reference electrode 6 is disposed in the electrolyte layer 3 on the side close to the ion storage layer 4 and is isolated from the ion storage layer 4.

[0060] The reference electrode 6 is in direct contact with the electrolyte layer 3 and is not connected to the electrochromic layer 2 and the ion storage layer 4. The reference electrode 6 does not participate in the electrochromic reaction and is only used to provide an accurate potential reference for the electrochromic layer 2 for subsequent measurement and comparison.

[0061] Specifically, the potential of the working electrode (with the first conductive substrate layer 1 as the working electrode) changes with the applied current, while the reference electrode 6 provides a stable potential unaffected by the current, serving as a fixed potential reference. By measuring the potential difference between the working electrode and the reference electrode 6, the potential change of the working electrode can be accurately reflected, thereby determining the electrochemical state of the electrochromic material and further inferring changes in its optical state. By comparing with the stable potential provided by the reference electrode 6, the potential applied to the first conductive substrate layer 1 can be precisely controlled, thereby adjusting its spectral response and improving the electrochemical and spectral repeatability of the electrochromic device.

[0062] The electrochromic device structure also includes a working electrode connection layer 7 and a counter electrode connection layer 8, as shown in Figure 1. A lateral displacement is provided between the first conductive substrate layer 1 and the second conductive substrate layer 5. The electrochromic layer 2 is disposed above the first conductive substrate layer 1 in the region where the first conductive substrate layer 1 and the second conductive substrate layer 5 overlap. The working electrode connection layer 7 is disposed in the region on the first conductive substrate layer 1 that extends laterally relative to the second conductive substrate layer 5. The ion storage layer 4 is disposed below the second conductive substrate layer 5 in the region where the first conductive substrate layer 1 and the second conductive substrate layer 5 overlap. The counter electrode connection layer 8 is disposed in the region on the second conductive substrate layer 5 that extends laterally relative to the first conductive substrate layer 1.

[0063] In this embodiment, the first conductive substrate layer 1 is used as the working electrode, the second conductive substrate layer 5 is used as the counter electrode, the working electrode connection layer 7 is disposed on the working electrode, and the counter electrode connection layer 8 is disposed on the counter electrode. When testing the electrochromic device, the working electrode connection layer 7 is used as the first electrode, and the counter electrode connection layer 8 is used as the second electrode. The working electrode connection layer 7 and the counter electrode connection layer 8 are respectively used to connect to the corresponding external circuits.

[0064] In this embodiment, the first conductive substrate layer 1, the second conductive substrate layer 5, and the reference electrode 6 can form a three-electrode two-loop circuit; wherein, the two loops include: a voltage loop formed by connecting the first conductive substrate layer 1 and the reference electrode 6 to an external circuit, and a current loop formed by connecting the first conductive substrate layer 1 and the second conductive substrate layer 5 to an external circuit.

[0065] Specifically, the positive and negative terminals of the external source meter are connected to the working electrode connection layer 7 and the counter electrode connection layer 8, respectively, to supply power to the electrochromic device. The working electrode connection layer 7 and the counter electrode connection layer 8 are connected to the ammeter to form a current loop. The working electrode connection layer 7 and the reference electrode 6 are connected to the voltmeter to form a voltage loop.

[0066] When the electrochromic device is voltage controlled, the relative potential between the working electrode connection layer 7 and the reference electrode 6 is observed by a voltmeter. Based on the observation result, the relative potential is precisely adjusted to the target value by a source meter.

[0067] When the electrochromic device is current controlled, the current between the working electrode connection layer 7 and the counter electrode connection layer 8 is observed by an ammeter. Based on the observation results, the current magnitude is precisely adjusted by a source meter. At the same time, the relative potential between the working electrode connection layer 7 and the reference electrode 6 can be monitored by a voltmeter to detect potential changes in a timely manner for adjustment.

[0068] In this embodiment, the equipment used to control the three electrodes and two circuits includes, but is not limited to, an electrochemical workstation, a source meter, a charge / discharge device, or a semiconductor test and analyzer.

[0069] The reference electrode 6 comprises an insulating flexible substrate and an electrode material, which is obtained by coating the electrode material onto the insulating flexible substrate and then curing it.

[0070] The materials of the reference electrode 6 include, but are not limited to, Ag / AgCl and lithium alloy; preferably, the reference electrode 6 is prepared by coating Ag / AgCl slurry onto an insulating flexible substrate.

[0071] The insulating flexible substrate is made of polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), polystyrene (PS), or polydimethylsiloxane (PDMS). Preferably, the insulating flexible substrate is a black substrate, which avoids the aging of the reference electrode 6 caused by light exposure.

[0072] The first conductive substrate 1 includes a transparent substrate and a conductive material (ITO) on the transparent substrate. Similarly, the second conductive substrate 5 also includes a transparent substrate and a conductive material on the transparent substrate. The conductive material of the first conductive substrate 1 is selected as a transparent conductive material or a reflective conductive material, and the conductive material of the second conductive substrate 5 is selected as a transparent conductive material.

[0073] The electrochromic layer 2 and the working electrode connection layer 7 are both disposed on the conductive material side of the first conductive substrate layer 1, and the ion storage layer 4 and the counter electrode connection layer 8 are both disposed on the conductive material side of the second conductive substrate layer 5.

[0074] The transparent substrate is made of glass or PET (polyethylene terephthalate, a commonly used polymer plastic); the transparent conductive material is made of one or more of the following: indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), and silver nanowires; the reflective conductive material is made of silver, gold, and aluminum.

[0075] The electrochromic layer 2 material is selected from conductive polymer electrochromic materials and inorganic oxide electrochromic materials; wherein, the conductive polymer electrochromic material is a polymer or copolymer of one or more materials selected from the group consisting of: aniline, pyrrole, thiophene, 3-hexylthiophene, 3,4-ethylenedioxythiophene, o-phenylenediamine, m-phenylenediamine, o-toluidine, o-methoxyaniline, o-aminobenzenesulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid and thieno[3,4-B]-1,4-dioxin-2-methanol; the inorganic oxide electrochromic material includes, but is not limited to, tungsten oxide, vanadium oxide, titanium oxide, nickel oxide, molybdenum oxide, and Prussian blue.

[0076] In this embodiment, the steps for encapsulating the reference electrode 6 into the electrochromic device are as follows:

[0077] S101: The reference electrode 6 is attached to the electrochromic layer 2 film with insulating double-sided adhesive, wherein the area of ​​the insulating double-sided adhesive is larger than the area of ​​the side of the reference electrode 6 closest to the electrochromic layer 2 film (i.e. the insulating double-sided adhesive is placed between the reference electrode 6 and the electrochromic layer 2 to isolate the reference electrode 6 and the electrochromic layer 2).

[0078] S102: The electrochromic layer 2 film after the reference electrode 6 is attached is connected to the ion storage layer 4 film through acrylic foam (VHB) adhesive, wherein a cavity is left in the central area of ​​the VHB adhesive.

[0079] S103: The electrolyte is injected into the cavity using a syringe, so that the side of the reference electrode 6 away from the electrochromic layer 2 film is in direct contact with the electrolyte (that is, the effective material surface of the reference electrode 6 is exposed in the electrolyte).

[0080] S104: Seal the device around its perimeter using ultraviolet (UV) curing adhesive or epoxy adhesive.

[0081] In this embodiment, a liquid electrolyte can be used to make the electrolyte layer 3, such as the electrolyte in S103 above. Alternatively, a gel electrolyte can be used, such as a gel electrolyte. When using a gel electrolyte, the content of S103 above is replaced by: spin-coating or scraping the gel electrolyte onto the ion storage layer 4 film and attaching it to the electrochromic layer 2 film after the reference electrode 6 is attached, so that the side of the reference electrode 6 away from the electrochromic layer 2 film is in direct contact with the gel electrolyte.

[0082] Preferably, when testing the electrochromic layer 2, the reference electrode 6 is attached to the side close to the working electrode to reduce the distance between the reference electrode 6 and the working electrode, thereby reducing the resistance caused by the electrolyte layer 3.

[0083] In this embodiment, the reference electrode 6 can also be attached to the ion storage layer film with insulating double-sided adhesive. The remaining operations are similar to those in S101 to S104 described above, and will not be repeated here.

[0084] In this embodiment, the electrochromic device can be a partitioned or patterned device, that is, the electrochromic device can include one or more independent working electrodes; in the partitioned or patterned device, different regions containing independent working electrodes can share the same reference electrode 6.

[0085] In this embodiment, if the electrochromic device introduces two reference electrodes 6, one reference electrode 6 can be disposed in the electrolyte layer 3 near the electrochromic layer 2, and the other reference electrode 6 can be disposed in the electrolyte layer 3 near the ion storage layer 4. The first conductive substrate layer 1, the second conductive substrate layer 5, and the two reference electrodes 6 together constitute a four-electrode device. During use, the reference electrode near the electrochromic layer 2 can be used as the third electrode, and the reference electrode near the ion storage layer 4 can be used as the fourth electrode. The voltage loop formed by connecting the first conductive substrate layer 1 and the third electrode to the external circuit, the current loop formed by connecting the first conductive substrate layer 1 and the second conductive substrate layer 5 to the external circuit, and the fourth electrode can be matched with any one of the first conductive substrate layer 1, the second conductive substrate layer 5, or the third electrode to form a voltage loop after being connected to the external circuit.

[0086] When two reference electrodes 6 are introduced, the other reference electrode 6 can be attached to the ion storage layer 4 using the same method based on the above steps S101 to S104. The steps for encapsulating the two reference electrodes 6 into the electrochromic device are as follows:

[0087] S201: The first reference electrode is attached to the electrochromic layer 2 film with insulating double-sided adhesive, such that the area of ​​the insulating double-sided adhesive is larger than the area of ​​the first reference electrode on the side close to the electrochromic layer 2 film. The second reference electrode is attached to the ion storage layer 4 film with insulating double-sided adhesive, such that the area of ​​the insulating double-sided adhesive is larger than the area of ​​the second reference electrode on the side close to the ion storage layer 4 film.

[0088] S202: The electrochromic layer 2 film after the first reference electrode is attached is connected to the ion storage layer 4 film after the second reference electrode is attached using VHB adhesive, wherein a cavity is left in the central area of ​​the VHB adhesive.

[0089] S203: The electrolyte is injected into the cavity using a syringe, so that the side of the first reference electrode away from the electrochromic layer 2 film is in direct contact with the electrolyte, and the side of the second reference electrode away from the ion storage layer 4 film is in direct contact with the electrolyte.

[0090] S204: Seal the device around its perimeter using ultraviolet (UV) curing adhesive or epoxy adhesive.

[0091] This embodiment provides a method for fabricating an electrochromic device including a reference electrode, comprising:

[0092] Step 1: Prepare a reference electrode 6 of a predetermined size;

[0093] In this embodiment, the reference electrode 6 can be prepared by a wet process. Specifically, the reference electrode material is coated on the prepared substrate, subjected to thermal annealing, and after curing, it is cut to a predetermined size to obtain the reference electrode 6.

[0094] Step 2: Coat an electrochromic layer material on the first conductive substrate layer 1 and perform heat annealing. After curing, remove the electrochromic material of a predetermined width from one side edge to form an electrochromic layer 2. Then, attach conductive adhesive at the location where the material was removed to form a working electrode connection layer 7.

[0095] In this embodiment, an electrochromic layer material is coated on one side of the first conductive substrate layer 1 where the conductive material (ITO) is disposed. A specific width of the edge of one side of the ITO surface is designated as the first predetermined position. After removing the electrochromic layer material at the first predetermined position, conductive adhesive is used to attach the exposed ITO surface to form the working electrode connection layer 7. The conductive adhesive can be copper foil conductive adhesive.

[0096] Step 3: The reference electrode 6 is attached to the electrochromic layer 2 with insulating double-sided adhesive, wherein the area of ​​the insulating double-sided adhesive is larger than the area of ​​the reference electrode 6 on the side closest to the electrochromic layer 2.

[0097] In this embodiment, insulating double-sided adhesive is used for bonding and isolation. The reference electrode 6 is not connected to the electrochromic layer 2 and does not participate in the electrochromic reaction.

[0098] Step 4: Coat the second conductive substrate layer 5 with ion storage layer material and perform heat annealing treatment. After it has cured, remove the ion storage layer material of a predetermined width from one side edge to form ion storage layer 4. Then, attach conductive adhesive at the location where the material was removed to form counter electrode connection layer 8.

[0099] In this embodiment, an ion storage layer material is coated on one side of the second conductive substrate layer 5 where the conductive material (ITO) is disposed. A specific width of the edge of one side of the ITO surface is designated as a second predetermined position. After removing the ion storage layer material at the second predetermined position, conductive adhesive is used to attach the exposed ITO surface to form the counter electrode connection layer 8.

[0100] Step 5 involves bonding the electrochromic layer 2 to the ion storage layer 4, and placing an electrolyte layer 3 between the electrochromic layer 2 and the ion storage layer 4 to form an electrochromic device, specifically including:

[0101] The electrochromic layer 2 after the reference electrode 6 is attached is bonded to the ion storage layer 4 with adhesive. A cavity is set in the central area of ​​the adhesive, and liquid electrolyte is injected into the cavity to form an electrolyte layer 3, so that the reference electrode 6 is in direct contact with the liquid electrolyte. Alternatively, a gel electrolyte is coated on the ion storage layer 4 to form an electrolyte layer 3, and the ion storage layer 4 coated with the gel electrolyte is bonded to the electrochromic layer 2 film after the reference electrode 6 is attached, so that the reference electrode 6 is in direct contact with the gel electrolyte.

[0102] Step 6: Seal the edges of the electrochromic device using encapsulating adhesive 9.

[0103] In this embodiment, the reference electrode 6 can also be attached to the ion storage layer film with insulating double-sided adhesive. The remaining operations are similar to those in steps 1 to 6 above, and will not be described again here.

[0104] In this embodiment, when preparing the electrochromic device using the methods described in steps 1 to 6 above, multiple reference electrodes 6 can also be introduced. For example, when two reference electrodes 6 are introduced, the two reference electrodes 6 can be respectively attached to the electrochromic layer 2 and the ion storage layer using insulating double-sided adhesive. This will not be elaborated further here.

[0105] In this embodiment, the electrochromic device including the reference electrode 6 can be applied to voltage and current measurement and control. Specifically, the positive and negative terminals of the external source meter (i.e., the power supply) can be connected to the working electrode connection layer 7 and the counter electrode connection layer 8 respectively to supply power to the electrochromic device. The working electrode connection layer 7 and the counter electrode connection layer 8 can be connected to the ammeter to form a current loop. The working electrode connection layer 7 and the reference electrode 6 can be connected to the voltmeter to form a voltage loop.

[0106] When the electrochromic device is voltage controlled, the relative potential between the working electrode connection layer 7 and the reference electrode 6 is observed by a voltmeter. Based on the observation results, the relative potential is precisely adjusted to the target value by a source meter. When the electrochromic device is current controlled, the current between the working electrode connection layer 7 and the counter electrode connection layer 8 is observed by an ammeter. Based on the observation results, the current magnitude is precisely adjusted by a source meter.

[0107] Electrochromic devices containing reference electrodes can also be applied to electrochromic spectroscopy research. Specifically, the positive and negative electrodes of the source meter can be connected to the working electrode connection layer 7 and the counter electrode connection layer 8, respectively, to power the electrochromic device. The working electrode connection layer 7 is used as the first electrode, the counter electrode connection layer 8 is used as the second electrode, and the reference electrode 6 near the electrochromic layer 2 is used as the third electrode. The first electrode and the third electrode are connected to the voltmeter to form a voltage loop.

[0108] Using the potential of the third electrode as a reference, the potential of the first electrode is adjusted to different target potentials through the source table. The spectral response of the electrochromic layer 2 corresponding to different target potentials is obtained, and the spectral characteristics of the electrochromic layer 2 at different target potentials are recorded to form a database for spectral research, so as to facilitate subsequent spectral studies.

[0109] Electrochromic devices containing reference electrodes can also be used in the analysis of potential matching. Specifically, the reference electrode near the electrochromic layer 2 can be used as the third electrode, and the reference electrode near the ion storage layer 4 can be used as the fourth electrode.

[0110] When measuring the potential change of the electrochromic layer 2, the positive and negative terminals of the first source meter are connected to the first and third electrodes respectively to supply power to the electrochromic device. The first and third electrodes are connected to the voltmeter to form the first voltage loop. The first source meter is used to repeatedly scan within the set potential range (e.g., from -1V to +1V and then back to -1V) to record the first potential change curve between the first and third electrodes.

[0111] When measuring the potential change of the ion storage layer 4, the positive and negative terminals of the second source meter are connected to the fourth and second electrodes respectively to supply power to the electrochromic device. The fourth and second electrodes are connected to the voltmeter to form a second voltage loop. The second source meter is used to repeatedly scan within the set potential range to record the second potential change curve between the fourth and second electrodes.

[0112] Based on the first and second potential change curves, the potential matching between the electrochromic layer and the ion storage layer can be analyzed. Materials for fabricating the electrochromic layer and the ion storage layer can be selected based on the potential matching between the two layers. The specific steps include the following:

[0113] S301: Select one of the two sets of candidate materials as the electrochromic layer and the ion storage layer respectively, and fabricate the electrochromic device using the methods in steps 1 to 6;

[0114] S302: Connect the electrochromic device to the external first source meter and second source meter according to the above method. Use the first source meter to scan repeatedly within the set potential range to obtain the first potential change curve of the electrochromic layer. At the same time, use the second source meter to monitor the potential and obtain the second potential change curve of the ion storage layer.

[0115] In the above process of potential monitoring using the second source meter, the source meter can act as a high-impedance voltmeter and continuously measure the potential of the ion storage layer. In actual operation, a current of 10nA is continuously applied to the output terminal of the second source meter (the current here is much smaller than the device current, so it will not affect the actual operation of the device). The receiving end of the second source meter continuously monitors the potential change of the ion storage layer and obtains the corresponding potential change curve.

[0116] S303: Within the set potential range, observe whether the changing directions of the first potential change curve and the second potential change curve are opposite. If they are not opposite, it is determined that the potentials of the electrochromic layer and the ion storage layer are mismatched. If they are opposite, the second potential change curve is reversed vertically (that is, the second potential change curve is vertically reversed with the horizontal line where the midpoint of the potential range is located as the reference, so that the changing direction of the second potential change curve is the same as that of the first potential change curve). The two points with corresponding horizontal coordinates in the first potential change curve and the reversed second potential change curve are taken as a set of comparison points. The average distance between the comparison points is calculated. When the average distance is greater than the preset threshold, it is determined that the potentials of the electrochromic layer and the ion storage layer are mismatched. When the average distance is less than or equal to the preset threshold, it is determined that the potentials of the electrochromic layer and the ion storage layer are matched.

[0117] The materials used in the potential-matched electrochromic layer and ion storage layer, as well as the corresponding potential ranges, are recorded.

[0118] S304: Update the set potential range, rescan the electrochromic layer and ion storage layer where the potentials do not match, obtain the updated first potential change curve and second potential change curve, and determine whether the potentials of the electrochromic layer and ion storage layer match according to the method in S303. When the potentials of the electrochromic layer and ion storage layer match, record the currently used material and the corresponding potential range. When the potentials of the electrochromic layer and ion storage layer match, continue to update the set potential range and perform potential matching judgment until the preset number of iterations ends.

[0119] It should be noted that, ideally, for an electrochromic device without polarization, the number of electrons gained and lost at the electrodes of the electrochromic layer and the ion storage layer is equal. Furthermore, when the applied voltage changes or is reversed, there is no charge accumulation on the two electrode materials. Therefore, the two potential change curves change in opposite directions. That is, when the control voltage curve is the first potential change curve, if the material at the other electrode can also remain unpolarized or fail within this potential range, its second potential change curve will change in opposite directions to the first potential change curve. The closer the degree of change, the higher the degree of matching. There may be instantaneous maxima in the curves, but these maxima are ignored in the calculation. Therefore, more suitable materials for fabricating the electrochromic layer and ion storage layer can be selected based on the potential matching between the electrochromic layer and the ion storage layer. Furthermore, theoretically, the peaks in the first potential change curve and the second potential change curve that show opposite directions are not corresponding. Instead, the peak of the second potential change curve appears after a certain period of time after the peak of the first potential change curve appears. When determining whether the directions of change of the first potential change curve and the second potential change curve are opposite, the situation where the peak of the first potential change curve appears after a certain period of time is considered to be opposite (theoretically, the two curves are generally opposite but not very similar, or opposite and highly similar), as shown by the black line (corresponding to the first potential change curve) and the red line (corresponding to the second potential change curve) in Figure 6.

[0120] In steps S301 to S304 above, the matching between the electrochromic layer and the ion storage layer is determined by the distance between two corresponding points on the horizontal axis. Pearson correlation coefficient or variance can also be used as a reference. Furthermore, this method can guide us to quickly screen suitable electrochromic material-ion storage layer material pairs by using different materials or varying the film thickness of the same material. This ensures that the voltages of both layers are within the reasonable voltage thresholds of the material during device operation. Especially when the ion storage layer material is also an electrochromic material, its potential range in the actual device can be effectively controlled, preventing over-oxidation or over-reduction that could lead to rapid degradation of the material's lifetime.

[0121] In this embodiment, the electrochromic device can be connected to an external circuit. Current and voltage are applied to the electrochromic device through the external circuit, such as a Keithley 2400 source meter. The voltage and current at different electrodes can be measured using existing measuring instruments, such as an electrochemical station. The source meter has two functions: a power source and a voltmeter (current meter). When used as a voltage source, it outputs voltage between the positive and negative electrodes and simultaneously returns the current in the circuit between them. Similarly, when used as a current source, it outputs current between the two electrodes and simultaneously measures the voltage in the circuit between them.

[0122] In this embodiment, the electrochromic device can be a patterned electrochromic device prepared by the methods of steps 1 to 6 described above. The patterned electrochromic device includes at least one reference electrode 6 and one or more electrochromic layers 2 distributed according to a predetermined pattern. The reference electrode 6 can serve as a common electrode for all regions where the electrochromic layers 2 are located, and can provide a uniform potential reference for all regions where the electrochromic layers 2 are located.

[0123] Example 1:

[0124] A three-electrode polyaniline electrochromic device was fabricated using Ag / AgCl material as the reference electrode. The specific operation is as follows:

[0125] S401: Apply Ag / AgCl slurry onto a PET substrate, anneal it on a 120℃ hot plate for 30 minutes, and after it is completely cured, cut the PET into strips of 0.5cm×3cm to serve as Ag / AgCl reference electrodes.

[0126] S402: Spin-coat chemically polymerized PANI:PSS onto an ITO glass substrate, anneal it on a 130°C hot plate for 10 minutes, wipe off the 0.5cm wide electrochromic material at the edge of the film, and use copper foil conductive tape to attach the exposed ITO glass.

[0127] S403: The Ag / AgCl reference electrode is attached to the PANI:PSS film with insulating double-sided adhesive tape, so that its short side is perpendicular to the copper foil conductive tape.

[0128] S404: Apply VHB adhesive with a 1.2×1.7cm through hole in the center to another clean ITO glass substrate, and apply copper foil conductive tape to the area of ​​the ITO glass substrate where no VHB adhesive is applied.

[0129] S405: Adhere the PANI:PSS film to the other side of the VHB adhesive, so that the through hole in the center of the VHB adhesive forms a cavity in the device. Use a syringe to inject formic acid into the device cavity as electrolyte layer 3.

[0130] S406: Use UV glue to seal the four edges of the device to obtain the No. 1 three-electrode polyaniline electrochromic device.

[0131] Figure 7 shows a physical image of the No. 1 three-electrode polyaniline electrochromic device prepared in Example 1. The No. 1 three-electrode polyaniline electrochromic device was tested as follows:

[0132] The No. 1 three-electrode polyaniline electrochromic device was tested using a Chenhua 604D electrochemical workstation, and the CV curve (scan rate of 100 mV / s) shown in Figure 2(a) was obtained. At the same time, the No. 1 three-electrode polyaniline electrochromic device was tested using an Avatens spectrometer combined with a deuterium tungsten lamp to build a transmittance test stage, and the electrochromic spectrum shown in Figure 2(b) was obtained.

[0133] Figure 3(a) shows the CV curve of the existing two-electrode device, and Figure 3(b) shows the spectrum of the existing two-electrode device. After comparison, it can be clearly found that in the No. 1 three-electrode polyaniline electrochromic device with Ag / AgCl reference electrode, the electrochromic voltage range is significantly reduced, and the electrochemical repeatability is significantly improved. The peak value of the cyclic voltammetry curve (CV curve) of the two-electrode device in Figure 3 changes continuously in each cycle, while the CV curve of the No. 1 three-electrode polyaniline electrochromic device in Figure 2 is basically the same. The spectral repeatability and stability of the No. 1 three-electrode polyaniline electrochromic device are improved, especially the improvement in long wavelengths (750nm, 850nm) is more obvious.

[0134] As shown in Figure 5(a), during cyclic voltammetry scanning of the three-electrode polyaniline electrochromic device, the voltage change between the positive electrode (i.e., electrochromic layer 2 / working electrode) and the counter electrode was monitored using a Keithley 2400 source meter. It was found that during the application of a voltage from -0.2V to +0.8V to the working layer, the voltage between the positive and negative electrodes (positive electrode is the working electrode, negative electrode is the counter electrode) changed from -2V to +1.6V, as shown in Figure 5(b). This change was caused by strong polarization in the device. Therefore, it can be seen that the CV curve obtained by using a two-electrode device for CV scanning has poor repeatability and a large difference from the actual situation.

[0135] Example 2: Based on Example 1, an ion storage layer was added. The ion storage layer was made of Pedot:PSS material. The second three-electrode polyaniline electrochromic device was prepared according to the methods in steps 1 to 6.

[0136] Figure 4(a) shows the cyclic voltammetry curve of the No. 2 three-electrode polyaniline electrochromic device during the 100-cycle test. Figure 4(b) shows the spectral repeatability of the electrochromic spectrum of the No. 2 three-electrode polyaniline electrochromic device within the 100-cycle test. Figure 4(c) shows the spectral repeatability of the electrochromic spectrum of the No. 2 three-electrode polyaniline electrochromic device in the first three cycles of the test. As can be seen from Figure 4(c), the No. 2 three-electrode polyaniline electrochromic device with a reference electrode has good electrochemical repeatability and spectral repeatability.

[0137] Example 3: Two identical Ag / AgCl reference electrodes were introduced, namely the first reference electrode and the second reference electrode. Three four-electrode polyaniline electrochromic devices were prepared according to the methods in steps 1 to 6, as shown in Figure 8. The first four-electrode polyaniline electrochromic device used Pedot:PSS material as the ion storage layer, the second four-electrode polyaniline electrochromic device used TiO2 material as the ion storage layer, and the third four-electrode polyaniline electrochromic device did not have an ion storage layer.

[0138] As shown in Figure 6(a), cyclic voltammetry scans were performed using the first reference electrodes of the three four-electrode polyaniline electrochromic devices, while a source meter was used to monitor the voltage change between the second reference electrode and the ion storage layer (counter electrode).

[0139] As can be seen from Figure 6(b), the voltage obtained varies greatly when different ion storage layers are used during the voltage control of the device. When Pedot:PSS material is used as the ion storage layer, the device exhibits good ion conductivity and electrochemical stability, and it can respond quickly to voltage changes with a relatively smooth voltage response curve. When TiO2 material is used as the ion storage layer, it can be clearly seen that the device responds slowly to voltage changes, and the voltage response curve is not smooth. TiO2 has relatively weak charge storage and transport capabilities as the ion storage layer, which affects the overall performance of the device. When there is no ion storage layer, the voltage response curve shows unstable voltage fluctuations, and the performance of the device is greatly affected.

[0140] By setting a reference electrode, we can obtain more accurate voltage division data in actual devices. This accurate data helps us understand the role of each functional layer in the device operation process. By analyzing this data, we can better select and optimize more suitable materials for each layer.

[0141] The steps in this application can be rearranged, combined, or deleted according to actual needs.

[0142] The units in the device of this application can be merged, divided, or deleted according to actual needs.

[0143] Although this application has been disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and not intended to limit the application of this application. The scope of protection of this application is defined by the appended claims and may include various modifications, alterations, and equivalents of the invention without departing from the scope and spirit of this application.

Claims

1. An electrochromic device structure including a reference electrode, comprising at least one reference electrode (6), and a first conductive substrate layer (1), an electrochromic layer (2), an electrolyte layer (3), an ion storage layer (4), and a second conductive substrate layer (5) stacked from bottom to top; The reference electrode (6) is disposed in the electrolyte layer (3) on the side close to the electrochromic layer (2), and the reference electrode (6) and the electrochromic layer (2) are isolated from each other; or, the reference electrode (6) is disposed in the electrolyte layer (3) on the side close to the ion storage layer (4), and the reference electrode (6) and the ion storage layer (4) are isolated from each other. The reference electrode (6) is in contact with the electrolyte layer (3) to provide a potential reference for the electrochromic layer (2).

2. The electrochromic device structure comprising a reference electrode of claim 1, wherein, The electrochromic device structure also includes a working electrode connection layer (7) and a counter electrode connection layer (8); The first conductive substrate layer (1) and the second conductive substrate layer (5) are laterally displaced. The electrochromic layer (2) is disposed above the first conductive substrate layer (1) and in the area where the first conductive substrate layer (1) and the second conductive substrate layer (5) overlap each other. The working electrode connection layer (7) is disposed in the area on the first conductive substrate layer (1) that extends laterally relative to the second conductive substrate layer (5). The ion storage layer (4) is disposed below the second conductive substrate layer (5) in the region where the first conductive substrate layer (1) and the second conductive substrate layer (5) overlap each other, and the counter electrode connection layer (8) is disposed on the second conductive substrate layer (5) in the region that extends laterally relative to the first conductive substrate layer (1).

3. The electrochromic device structure comprising a reference electrode of claim 1, wherein, The reference electrode (6) includes an insulating flexible substrate and an electrode material. The electrode material is coated on the insulating flexible substrate. The material of the reference electrode (6) is selected from Ag or AgCl. The material of the insulating flexible substrate is selected from polyethylene terephthalate, polyimide, polypropylene, polystyrene or polydimethylsiloxane. The electrochromic layer (2) is made of a conductive polymer electrochromic material, which is a polymer or copolymer of one or more materials selected from the group consisting of: aniline, pyrrole, thiophene, 3-hexylthiophene, 3,4-ethylenedioxythiophene, o-phenylenediamine, m-phenylenediamine, o-toluidine, o-methoxyaniline, o-aminobenzenesulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid and thieno[3,4-B]-1,4-dioxin-2-methanol.

4. A method for fabricating an electrochromic device including a reference electrode, comprising: Step 1, prepare a reference electrode of a predetermined size (6); Step 2: Coat an electrochromic layer material on the first conductive substrate layer (1), and after it has cured, remove the electrochromic layer material of a predetermined width from one side edge, and set a working electrode connection layer (7) at the location where the material was removed. Step 3: The reference electrode (6) is attached to the electrochromic layer (2) with insulating double-sided adhesive tape, wherein the area of ​​the insulating double-sided adhesive tape is larger than the area of ​​the reference electrode (6) on the side close to the electrochromic layer (2). Step 4: Coat the second conductive substrate layer (5) with ion storage layer material, and after it has cured, remove the ion storage layer material of a predetermined width from one side edge, and set the counter electrode connection layer (8) at the location where the material was removed. Step 5: The electrochromic layer (2) is bonded together with the ion storage layer (4), and an electrolyte layer (3) is disposed between the electrochromic layer (2) and the ion storage layer (4); Step 6: Seal the edges of the electrochromic device.

5. The method for producing an electrochromic device comprising a reference electrode according to claim 4, wherein, Step 1 includes: coating a reference electrode material onto a prepared substrate, performing a heat annealing treatment, and cutting it to a predetermined size after it has solidified to obtain a reference electrode (6).

6. The method for producing an electrochromic device comprising a reference electrode according to claim 4, wherein, Step 5 includes: The electrochromic layer (2) is bonded to the ion storage layer (4) with adhesive. A cavity is formed in the center of the adhesive, and liquid electrolyte is injected into the cavity, so that the reference electrode (6) is in direct contact with the liquid electrolyte. Alternatively, a gel electrolyte can be coated onto the ion storage layer (4), and the ion storage layer (4) and the electrochromic layer (2) film can be bonded together so that the reference electrode (6) is in direct contact with the gel electrolyte.

7. Use of an electrochromic device as claimed in claim 1 for voltage current measurement and control, wherein, Connect the positive and negative terminals of the external source meter to the working electrode connection layer (7) and the counter electrode connection layer (8) respectively to supply power to the electrochromic device. Connect the working electrode connection layer (7) and the counter electrode connection layer (8) to the ammeter to form a current loop. Connect the working electrode connection layer (7) and the reference electrode (6) to the voltmeter to form a voltage loop. When the electrochromic device is voltage controlled, the relative potential between the working electrode connection layer (7) and the reference electrode (6) is observed by a voltmeter. Based on the observation results, the relative potential is precisely adjusted to the target value by a source meter. When controlling the current of the electrochromic device, the current between the working electrode connection layer (7) and the counter electrode connection layer (8) is observed by an ammeter, and the current magnitude is precisely adjusted by the source meter based on the observation results.

8. Use of an electrochromic device as claimed in claim 1 in electrochromic spectroscopic studies, wherein, The positive and negative terminals of the source meter are connected to the working electrode connection layer (7) and the counter electrode connection layer (8) respectively to supply power to the electrochromic device. The working electrode connection layer (7) is used as the first electrode, the counter electrode connection layer (8) is used as the second electrode, and the reference electrode (6) near the electrochromic layer (2) is used as the third electrode. The first electrode and the third electrode are connected to the voltmeter respectively to form a voltage loop, wherein the source meter is used to supply power. Using the potential of the third electrode as a reference, the potential of the first electrode is adjusted to different target potentials through the source table, and the spectral response of the electrochromic layer (2) corresponding to different target potentials is obtained. The spectral characteristics of the electrochromic layer (2) under different target potentials are recorded to form a database for spectral research.

9. Use of an electrochromic device as claimed in claim 1 for potentiometric analysis, wherein, The electrochromic device includes two reference electrodes (6), one of which is close to the electrochromic layer (2) and the other is close to the ion storage layer (4). The working electrode connection layer (7) is used as the first electrode, the counter electrode connection layer (8) is used as the second electrode, the reference electrode close to the electrochromic layer (2) is used as the third electrode, and the reference electrode close to the ion storage layer (4) is used as the fourth electrode. When measuring the potential change of the electrochromic layer (2), the positive and negative terminals of the first source meter are connected to the first electrode and the third electrode respectively to supply power to the electrochromic device. The first electrode and the third electrode are connected to the voltmeter respectively to form the first voltage circuit. The first source meter is used to scan repeatedly within the set potential range to record the first potential change curve between the first electrode and the third electrode. When measuring the potential change of the ion storage layer (4), the positive and negative terminals of the second source meter are connected to the fourth and second electrodes respectively to supply power to the electrochromic device. The fourth and second electrodes are connected to the voltmeter respectively to form a second voltage circuit. The second source meter is used to scan repeatedly within the set potential range to record the second potential change curve between the fourth and second electrodes. Based on the first and second potential change curves, the potential matching between the electrochromic layer and the ion storage layer is calculated. Materials for fabricating the electrochromic layer and the ion storage layer are then selected based on the potential matching between the two layers. The specific steps include the following: S301: Select one material from each of the two groups of candidate materials to serve as the electrochromic layer and the ion storage layer, respectively, and fabricate an electrochromic device; S302: The first potential change curve of the electrochromic layer is obtained by repeatedly scanning within the set potential range using the first source meter. At the same time, the second potential change curve of the ion storage layer is obtained by monitoring the potential using the second source meter. S303: Within the set potential range, observe whether the change directions of the first potential change curve and the second potential change curve are opposite. If they are not opposite, it is determined that the potentials of the electrochromic layer and the ion storage layer are mismatched. If they are opposite, the second potential change curve is reversed in the vertical direction. The two points corresponding to the horizontal coordinates in the first potential change curve and the reversed second potential change curve are taken as a set of comparison points. The average distance between the comparison points is calculated. When the average distance is greater than the preset threshold, it is determined that the potentials of the electrochromic layer and the ion storage layer are mismatched. When the average distance is less than or equal to the preset threshold, it is determined that the potentials of the electrochromic layer and the ion storage layer are matched. The materials used in the potential-matched electrochromic layer and ion storage layer, as well as the corresponding potential ranges, are recorded. S304: Update the set potential range, rescan the electrochromic layer and ion storage layer where the potentials do not match, obtain the updated first potential change curve and second potential change curve, and determine whether the potentials of the electrochromic layer and ion storage layer match according to the method in S403. When the potentials of the electrochromic layer and ion storage layer match, record the currently used material and the corresponding potential range. When the potentials of the electrochromic layer and ion storage layer match, continue to update the set potential range and perform potential matching judgment until the preset number of iterations is reached.

10. A patterned electrochromic device comprising at least one reference electrode (6) and one or more electrochromic layers (2) distributed according to a predetermined pattern, prepared by the method of claim 4, wherein, The reference electrode (6) is a common electrode for all regions where the electrochromic layer (2) is located, and is used to provide a uniform potential reference for all regions where the electrochromic layer (2) is located.

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