JP2013114144A - Electrochromic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochromic device using a new electrolyte layer.SOLUTION: An electrochromic device 1 including a pair of electrode layers 2 and 3 facing each other with a space provided in a height direction between them, electrochromic layers 5 and 7 held between the electrode layers 2 and 3, and an electrolyte layer 8 in contact with an electrochromic layers 5 and 7. The electrolyte layer 8 is made by impregnating a porous layer 9 with electrolyte 10. In the porous layer 9, a top face 9a and a bottom face 9b face each other in the height direction, and continuous pores 11 are formed so as to continue from the top face 9a to the bottom face 9b.

Description

  The present invention relates to an electrochromic element in which an electrochromic layer and an electrolyte layer are sandwiched between a pair of electrode layers spaced in the height direction.

  The electrochromic element has a structure in which an electrochromic layer and an electrolyte layer are sandwiched between a pair of electrode layers spaced apart in the height direction, as shown in the patent literature. A liquid electrolyte or a gel electrolyte can be used for the electrolyte layer.

  However, conventionally, the electrolyte layer is expensive, and when the substrate is changed from glass to a film, there is a problem that the thickness of the electrolyte layer tends to vary.

JP 2002-341387 A JP 2010-101982 A Japanese Patent Laid-Open No. 11-86908

  Accordingly, an object of the present invention is to provide an electrochromic device using a new electrolyte layer that can improve the conventional problems.

The present invention, in an electrochromic device having a pair of electrode layers facing each other with a gap in the height direction, an electrochromic layer sandwiched between each electrode layer and an electrolyte layer in contact with the electrochromic layer,
The electrolyte layer is formed by impregnating a porous layer with an electrolytic solution, and the porous layer has continuous pores extending from the first surface to the second surface facing in the height direction. It is characterized by. According to the present invention, the electrolyte layer has a structure in which a porous layer is impregnated with an electrolytic solution, so that the amount of the electrolytic solution used can be reduced compared to the conventional case, and the cost can be reduced. Further, the thickness of the electrolyte layer can be determined by the thickness of the porous layer, and the thickness can be stabilized. In the present invention, the porous layer is provided with continuous pores that lead from the first surface facing the second surface to the second surface in the height direction. For this reason, electrolyte solution can be hold | maintained in a continuous pore and it becomes possible to obtain favorable responsiveness.

  In this invention, it is preferable that the said porous layer consists of a material swollen with the said electrolyte solution. In the present invention, the porous layer is preferably a silicone rubber sheet, but other rubber sheets can be substituted.

  Further, the present invention is suitable for a configuration in which the porous layer is whitened or colored. By whitening or coloring the porous layer in this way, white particles and colored particles do not collapse due to changes in the installation state that can occur when colored particles or white particles are dispersed in a conventional gel electrolyte. Therefore, a stable white surface or colored surface can be obtained even if the installation state changes.

  Moreover, in this invention, it can also be set as the structure by which the white particle or colored particle is taken in in the said continuous pore. As a result, the white particles and the white particles are retained in the continuous pores, and the collapse of the white particles and the colored particles accompanying the change in the installation state that occurs when the colored particles and the white particles are dispersed in the conventional gel electrolyte occurs. Therefore, even if the installation state changes, a stable white surface or colored surface can be obtained.

  In the present invention, it is preferable that a sealing layer having substantially the same height as the electrolyte layer is provided around the electrolyte layer. As a result, electrolyte leakage can be prevented.

  Moreover, in this invention, it is preferable that the said sealing layer is integrally formed with the said porous layer as a layer without the said continuous pore. As a result, the sealing layer can be appropriately formed around the electrolyte layer with no gap and at the same height, so that liquid leakage can be effectively prevented, and the porous layer and the sealing layer can be formed of the same material. Reduction can be achieved.

  Moreover, in this invention, it is preferable that the electrochromic layers formed in the inner surface of each electrode layer which mutually opposes at intervals are opposingly arranged by the said height direction through the said electrolyte layer. Thereby, responsiveness can be improved effectively.

  According to the present invention, the electrolyte layer has a structure in which a porous layer is impregnated with an electrolytic solution, so that the amount of electrolyte used can be reduced and cost can be reduced as compared with the prior art. In addition, when glass is used as the substrate, it is possible to stabilize the thickness of the electrolyte layer even when the glass is changed to a film. Moreover, in this invention, electrolyte can be hold | maintained in a continuous pore and it becomes possible to obtain favorable responsiveness.

FIG. 1 is a longitudinal sectional view of an electrochromic device according to a first embodiment of the present invention. FIG. 2 is an enlarged schematic view showing a part of the electrochromic element shown in FIG. FIG. 3A is an SEM photograph of the surface of the porous layer (silicone rubber sheet) in the present embodiment, and FIG. 3B is an SEM photograph of a cross section of the porous layer (silicone rubber sheet) in the present embodiment. is there. FIG. 4 is a longitudinal sectional view of an electrochromic device according to a second embodiment of the present invention. FIG. 5 is a plan view of the electrochromic element used in the experiment. FIG. 5A shows a state in which the first electrochromic layer and the second electrochromic layer are displaced in a plan view (a state in which they do not overlap). FIG. 5B shows a configuration in which the first electrochromic layer and the second electrochromic layer face each other in the film thickness direction. FIG. 6 shows current values of responsiveness (color development → decoloration) in Examples 1 and 2 having a comparative example using a gel electrolyte and an electrolyte layer having a porous layer (silicone rubber sheet) having continuous pores. It is the graph calculated | required by the change. FIG. 7 shows current values of responsiveness (decoloration → color development) in Example 1 and Example 2 having an electrolyte layer provided with a porous layer (silicone rubber sheet) having continuous pores and a comparative example using a gel electrolyte. It is the graph calculated | required by the change. FIG. 8 is a comparative example using a gel electrolyte, in an example having an electrolyte layer provided with a porous layer (silicone rubber sheet) having continuous pores and formed with porosity of 50%, 55%, and 60%. It is the graph which calculated | required responsiveness (color development-> decoloring) by the electric current value change. FIG. 9 is a comparative example using a gel electrolyte, in an example having an electrolyte layer having a porous layer (silicone rubber sheet) having continuous pores and having a porosity of 50%, 55%, and 60%. It is the graph which calculated | required responsiveness (decoloration-> color development) by the electric current value change. FIG. 10 is a graph in which two types of examples shown in FIGS. 4A and 4B are used, and the responsiveness (color development → decoloration) in each example is obtained by changing the current value. FIG. 11 is a graph in which two types of examples shown in FIGS. 4A and 4B are used, and responsiveness (decoloration → color development) in each example is obtained by a change in current value. FIG. 12 is a graph obtained by using two types of examples shown in FIGS. 4A and 4B and determining the responsiveness (color development → decoloration) in each example by changing the charge amount. FIG. 13 is a graph in which the two types of examples shown in FIGS. 4A and 4B are used, and the responsiveness (decoloration → color development) in each example is obtained by changing the charge amount.

FIG. 1 is a partial longitudinal sectional view of an electrochromic element.
The electrochromic element 1 shown in FIG. 1 includes a pair of transparent electrode layers 2 and 3 spaced in the height direction (Z), and electrochromic layers 5 and 7 sandwiched between the transparent electrode layers 2 and 3. And an electrolyte layer 8 formed in contact with the electrochromic layers 5 and 7.

  Each of the transparent electrode layers 2 and 3 includes a transparent conductive layer 6 formed of indium tin oxide (ITO) on the inner surface of a transparent base material 4 such as glass. The transparent substrate 4 may be a film.

  As shown in FIG. 1, the first electrochromic layer 5 is formed on the conductive surface of the first transparent electrode layer 2. The first electrochromic layer 5 and the transparent conductive layer 6 are electrically connected. In FIG. 1, the first electrochromic layer 5 and the transparent conductive layer 6 are formed in contact with each other.

  A second electrochromic layer 7 is formed on the conductive surface of the second transparent electrode layer 3. The second electrochromic layer 7 and the transparent conductive layer 6 are electrically connected. In FIG. 1, the second electrochromic layer 7 and the transparent conductive layer 6 are formed in contact with each other.

  The electrochromic layers 5 and 7 can be formed by sputtering, field deposition, printing, or the like.

  In the embodiment shown in FIG. 1, the first electrochromic layer 5 and the second electrochromic layer 7 are opposed to each other with the electrolyte layer 8 interposed therebetween. The first electrochromic layer 5 and the second electrochromic layer 7 and the electrolyte layer 8 are formed in contact with each other.

For example, the first electrochromic layer 5 is obtained by applying ink containing Prussian blue (Fe ₄ [Fe (CN) ₆ ] ₃ ) by a spin coater, and the second electrochromic layer 7 is formed by nickel-substituted Prussian blue. An ink containing an analog (Ni ₃ [Fe (CN) ₆ ] ₂ ) is applied by a spin coater. In the present embodiment, the electrochromic material used as each of the electrochromic layers 5 and 7 is not limited.

  As shown in FIG. 1, a sealing layer 13 is provided around the electrolyte layer 8. As shown in FIG. 1, the sealing layer 13 is formed with substantially the same height (film thickness) as the electrolyte layer 8.

  In the present embodiment, as shown in the enlarged view of FIG. 2, the electrolyte layer 8 includes a porous layer 9 and an electrolytic solution 10.

  Here, as shown in FIG. 2 (schematic diagram), the porous layer 9 has a large number of continuous layers from the upper surface (first surface) 9a facing the lower surface (second surface) in the height direction (Z). The pores 11 are formed. In FIG. 2, only one continuous pore 11 is denoted by a reference numeral. As shown in FIG. 2, the continuous pores 11 may extend substantially parallel to the film thickness direction (Z), or may extend three-dimensionally into the electrolyte layer and communicate from the upper surface 9a to the lower surface 9b. Good. For example, in the cross section shown in FIG. 2, the pores 11 a and 11 b are cut in the middle, but actually, the pores 11 a and 11 b are connected to each other by extending in the back direction or the front direction of the drawing. Is configured.

  The diameter of the continuous pores 11 is preferably about several tens of μm to several hundreds of μm. The pores exist with a non-uniform diameter. Further, it is preferable that the continuous pores 11 are formed with respect to the electrolyte layer 8 with a porosity of about 50% to 60%. Thereby, favorable responsiveness and intensity | strength can be maintained appropriately, and a liquid leak can be prevented. In order to improve the responsiveness, it is desirable to increase the porosity of the rubber sheet. When the porosity is 55% or more, the responsiveness is almost equal to that of the element using the gel electrolyte.

  In this embodiment, although the material of the porous layer 9 is not limited, a silicone rubber sheet is preferably applied. FIG. 3 shows an SEM photograph of a silicone rubber sheet having continuous pores. 3A is a SEM photograph of the sheet surface, and FIG. 3B is a SEM photograph of the longitudinal section. The porosity (porosity) of the silicone rubber sheet shown in FIG. 3 was 50%. As the silicone rubber sheet, Sapolus (trade name) manufactured by Asahi Rubber Co., Ltd. was used. It was found that the silicone rubber sheet was formed with a large number of continuous pores leading from the upper surface to the lower surface. Further, the silicone rubber sheet can be formed with a film thickness of about 0.1 mm to 1.0 mm.

  The electrolyte layer 8 in this embodiment is formed by impregnating the porous layer 9 with the electrolytic solution 10. The impregnation is preferably performed by evacuation for several tens of minutes to several hours, and in some cases, several days.

  Here, the electrolytic solution 10 is an electrolytic solution in which perchlorate, iron complex, metal halide, alkali metal salt, alkaline earth metal salt, etc. are dissolved in ethers, carbonates, alcohols, esters, etc. as solvents. A liquid is preferred. In the present embodiment, the electrolytic solution 10 can be taken (held) into the continuous pores 11 formed in the porous layer 9. The electrolytic solution is preferably an electrolytic solution in which bis (trifluoromethanesulfonyl) imide potassium is dissolved in propylene carbonate. Alternatively, potassium tetrafluoroborate, potassium perchlorate, potassium hexafluorophosphate, potassium bis (fluorosulfonyl) imide, potassium trifluoromethanesulfonate, or the like can be used as the potassium salt and can be driven without any particular problem.

  In the electrochromic device 1 shown in FIGS. 1 and 2, an oxidation-reduction reaction occurs between the first electrochromic layer 5 and the second electrochromic layer 7 via the electrolyte layer 8, and the first electrochromic layer If 5 is colored, the second electrochromic layer 7 is decolored, while if the first electrochromic layer 5 is decolored, the second electrochromic layer 7 is colored.

  For example, the first electrochromic layer 5 is formed with Prussian blue (PB), which is an electrochromic material, and the second electrochromic layer 7 is formed of a nickel-substituted Prussian blue analog (NiPB), which is an electrochromic material. When the first electrochromic layer 5 is in an oxidized state, it has a bitumen color, while the second electrochromic layer 7 is in a reduced state and is decolored (transparent). Conversely, when the second electrochromic layer 7 is in an oxidized state, it exhibits a yellow color, while the first electrochromic layer 5 is in a reduced state and is decolored (becomes transparent).

  For example, if the surface of the first transparent electrode layer 2 shown in FIG. 1 is the display surface 2a and the electrode layer and the electrolyte are transparent or nearly transparent, the bitumen of the first electrochromic layer 5 from the display surface 2a. Along with the display, the yellow display in the second electrochromic layer 7 can be seen alternately.

Alternatively, the electrolyte layer 8 can be whitened or colored. For example, it is possible to whiten the porous layer 9 by kneading titanium oxide (TiO ₂ ), which is white particles (filler), into the porous layer 9. Alternatively, white particles such as titanium oxide can be added to the electrolytic solution 10. Thereby, white particles can be taken into the continuous pores 11 of the porous layer 9. In addition to the white particles, colored particles can be colored by kneading them into the porous layer 9 or by putting them in the electrolytic solution 10.

  By whitening or coloring the electrolyte layer 8 in this way, only the color of the first electrochromic layer 5 is displayed on the display surface 2a, and the color of the second electrochromic layer 7 is made invisible. Can do.

The sealing layer 13 provided around the electrolyte layer 8 shown in FIG. 1 is formed integrally with the porous layer 9 in FIG. In this embodiment, for example, the porous layer 9 and the sealing layer 13 can be formed of the same silicone rubber. At this time, the sealing layer 13 is formed as a layer without the continuous pores 11. For example, the porous layer 9 is formed by forming a silicone rubber sheet in which the continuous pores 11 are formed as a whole, and filling the continuous pores 11 by embedding a resin in the continuous pores 11 in the peripheral portion to be the sealing layer 13. And the sealing layer 13 without the continuous pores 11 can be formed easily and appropriately.
Alternatively, the porous layer 9 and the sealing layer 13 can be formed in two colors.

  In the present embodiment, since the electrolyte layer 8 has a structure in which the porous layer 9 is impregnated with the electrolytic solution 10, the amount of the electrolytic solution 10 used can be reduced as compared with the conventional case, and the cost can be reduced. That is, in the present embodiment, the entire electrolyte layer 8 is not an electrolyte, and the amount of the electrolyte solution 10 taken (held) into the continuous pores 11 formed in the porous layer 9 is sufficient. It can be effectively reduced. The porous layer 9 is preferably made of a material that swells with the electrolytic solution 10. In this embodiment, for example, the electrolyte layer 8 can be formed of a silicone rubber sheet. However, it is not limited to the silicone rubber sheet. In the present embodiment, the thickness of the electrolyte layer 8 can be determined by the thickness of the porous layer 9, and the thickness can be stabilized. Variation in film thickness can be reduced by molding the rubber sheet. In addition, when glass is used for the transparent substrate 4, the thickness of the electrolyte layer 8 can be stabilized even when the glass is changed to a film.

  In the present embodiment, the porous layer 9 is provided with continuous pores 11 leading from the upper surface 9a to the lower surface 9b. For this reason, the electrolytic solution 10 can be held in the continuous pores 11. Therefore, an oxidation-reduction reaction can be caused between the electrochromic layer 5 and the second electrochromic layer 7 through the electrolytic solution 10 held in the continuous pores 11, and a good responsiveness can be obtained. Become.

  In the configuration in which titanium oxide is mixed into the inside of the electrolyte layer using the conventional gel electrolyte and whitened, when the installation state is changed from the state where the electrochromic element is laid down, the titanium oxide and the gel-like structure Separated from the electrolyte, the titanium oxide collapses in the lower end direction of the electrolyte layer in the standing state (side portion direction in the lying state), and the titanium oxide in the upper portion of the electrolyte layer in the standing state There was a case where there was an area without any. For this reason, there has been a problem that a stable white surface cannot be obtained due to a change in the installation state, for example, a region where titanium oxide has collapsed appears transparent on the display surface.

  On the other hand, in the present embodiment, the porous layer 9 can be whitened or colored, so that the white particles or the like accompanying the change in the installation state (such as changing from a lying state to a standing state) as in the past Colored particles do not collapse, and therefore, a stable white surface or colored surface can be obtained even if the installation state changes. Alternatively, it is possible to adopt a configuration in which white particles and colored particles are taken into the continuous pores 11 without whitening or coloring the porous layer 9 together with whitening or coloring of the porous layer 9. As a result, the white particles and the colored particles are held in the continuous pores 11, so that the white particles and the colored particles are not collapsed due to the change in the installation state as in the prior art. A white surface or a colored surface can be obtained. When white particles or colored particles are put in the electrolytic solution 10, the diameter of the continuous pores 11 needs to be larger than the particle diameter. For example, titanium oxide has a nano-sized to several μm diameter, and can be taken into the continuous pores 11 having a diameter of several tens to several hundreds of μm.

  Moreover, in this embodiment, favorable whitening and coloration are realizable irrespective of specific gravity of particle | grains. Conventionally, the particles settled due to the difference in specific gravity between the electrolyte and the particles, which led to the collapse of the particles along with the change in the installation state of the electrochromic device, but in this embodiment, the specific gravity of the particles is large. For example, even when titanium oxide is used, by incorporating the particles into the continuous pores 11, a collapse phenomenon does not occur, and good whitening can be realized. Conventionally, for example, particles that are difficult to settle and adjustment of viscosity are required to prevent collapse, but in this embodiment, such adjustment is not particularly required, and the manufacturing cost can be reduced.

  Further, as shown in FIG. 1, by providing a sealing layer 13 having almost the same height as the electrolyte layer 8 around the electrolyte layer 8, the leakage of the electrolyte solution 10 can be prevented.

  Further, as shown in FIG. 2, it is preferable that the sealing layer 13 is integrally formed with the porous layer 9 as a layer without the continuous pores 11. As a result, the sealing layer 13 can be appropriately formed around the electrolyte layer 9 with no gap and at the same height to effectively prevent liquid leakage, and the porous layer 9 and the sealing layer 13 can be formed of the same material. The manufacturing cost can be reduced.

  In the electrochromic element 1 shown in FIGS. 1 and 2, the first electrochromic layer 5 and the second electrochromic layer 7 are opposed to each other in the film thickness direction (Z). On the other hand, in the second embodiment shown in FIG. 4, the first electrochromic layer 5 and the second electrochromic layer 7 are viewed in a plan view (arrow α) so as not to overlap in the film thickness direction (Z). They are arranged out of position.

  It is preferable that the electrochromic layers 5 and 7 are opposed to each other as shown in FIG. That is, as described with reference to FIG. 2, the porous layer 9 has continuous pores 11 extending from the upper surface 9a to the lower surface 9b, and the electrochromic layers 5 and 7 are arranged so as to be shifted as shown in FIG. As a result, the number of continuous pores 11 leading from the first electrochromic layer 5 to the second electrochromic layer 7 decreases. For this reason, if it is a form of FIG. 4, supply of the electrolyte solution 10 will become inadequate between each electrochromic layer 5 and 7, and a response will fall easily. Therefore, as shown in FIG. 1, the continuous pores 11 communicating between the electrochromic layers 5 and 7 are increased by making the first electrochromic layer 5 and the second electrochromic layer 7 face each other in the film thickness direction. The electrolyte solution 10 can be sufficiently supplied, and good responsiveness can be obtained.

(Experiment using three types of electrolyte layers)
In the experiment, as shown in the plan view of FIG. 5A, the first electrochromic layers 5 and 5 and the second electrochromic layers 7 and 7 are not opposed to each other in the film thickness direction and shifted in plan view. Arranged. The electrochromic elements in each sample were unified except for the configuration of the electrolyte layer. In each sample, an ink having Prussian blue (PB) was applied by spin coating to form the electrochromic layers 5 and 7.

As an electrolyte layer, a gel electrolyte in which polymethyl methacrylate resin (PMMA) is dissolved and titanium oxide (TiO ₂ ) is dispersed in an imide electrolyte solution (concentration 5 M) in which bis (trifluoromethanesulfonyl) imide potassium is dissolved in propylene carbonate ( Comparative Example), 0.3 mm thick silicone rubber sheet (orange) with continuous pores (uses Sapolus (trade name) manufactured by Asahi Rubber Co., Ltd., porosity (porosity) is 50%, pore diameter is several tens of μm Example 1 in which the electrolyte solution is immersed in about ~ 100 μm, a 1.0 mm thick silicone rubber sheet (transparent) having continuous pores (saporus (trade name) manufactured by Asahi Rubber Co., Ltd.) is used. (Porosity) is 50%, the pore diameter is about several tens of μm to several hundreds of μm, and the color and thickness of the rubber sheet are different from those of Example 1). Example 2 was used. In Examples 1 and 2, it was immersed in the electrolyte solution while removing air from the continuous pores under vacuum.

  For each sample, −1.5 V → 1.5 V (first electrochromic layer color development → decoloration), 1.5 V → −1.5 V (first electrochromic layer decoloration → color development) Chronoamperometry was measured under the conditions. For the measurement, a potentiostat (model number HZ-5000) manufactured by Hokuto Denko was used.

  The experimental results are shown in FIGS. The response was evaluated when the current stopped flowing. As a result, the response time in the comparative example and Examples 1 and 2 was about 10 to 15 seconds. However, in Example 2, the time required for color development → decoloration was about 7 seconds, whereas in the comparative example, it took about 10 seconds, and the responsiveness in Example 2 was superior. Moreover, in Example 2 and the comparative example, the time required for decoloring → color development was about 12 seconds, and the same result was obtained. From the above experimental results, it was found that in the example using the silicone rubber sheet having continuous pores, the same or better responsiveness as the comparative example of the gel electrolyte can be obtained.

(Experiment of porosity)
In the experiment, an electrochromic element having a porosity of 50%, 55%, and 60% of the silicone rubber sheet used in Example 1 was prepared. In the experiment, two types of silicone rubber sheets having a porosity of 50% were used. Two types of silicone rubber sheets having a rate of 55% and three types of silicone rubber sheets having a porosity of 60% were prepared. The first electrochromic layer 5 used in the experiment was formed by applying an ink having Prussian blue (PB) by spin coating, and the second electrochromic layer 7 was formed by using a nickel-substituted Prussian blue analog (Ni ₃ [ An ink having Fe (CN) ₆ ] ₂ ) was applied by spin coating. Other configurations were the same as those in the above experiment.

  For each sample, the chrono is applied under the conditions of −0.8 V → 0 V (color development → decoloration of the first electrochromic layer) and 0V → −0.8 V (decoloration → color development of the first electrochromic layer). Amperometry was measured. For the measurement, a potentiostat (model number HZ-5000) manufactured by Hokuto Denko was used.

  The experimental results are shown in FIGS. As shown in FIGS. 8 and 9, it was found that the responsiveness improved as the porosity increased. Moreover, it turned out that the responsiveness equivalent to a gel electrolyte can be acquired, so that the porosity of a rubber sheet approaches 60%.

  According to this experiment, it is preferable to use a rubber sheet having a porosity of about 50% to 60%, and by using a rubber sheet having a porosity of about 55% to 60%, an electrochromic element using a gel electrolyte and It was set to be more preferable because it can show almost the same response.

(Experiment to compare the pattern with the electrochromic layer facing and the shifted pattern)
In the plan view of FIG. 5B, the first electrochromic layers 5 and 5 and the second electrochromic layers 7 and 7 are arranged to face each other in the film thickness direction.

  In the experiment, an electrochromic element using a 0.3 mm-thick silicone rubber sheet having continuous pores of Example 1 was used. In addition, about the immersion method of electrolyte solution, the material of an electrochromic layer, etc., it is the same as that of the said experiment.

  The experiment was performed using the patterns shown in FIGS. 5 (a) and 5 (b). That is, as shown in FIG. 5A, the patterns of the first electrochromic layer 5 and the second electrochromic layer 7 are shifted so as not to overlap in the film thickness direction, as shown in FIG. 5B. Two types were prepared in which the patterns of the first electrochromic layer 5 and the second electrochromic layer 7 were opposed in the film thickness direction.

  For each sample, −1.5 V → 1.5 V (first electrochromic layer color development → decoloration), 1.5 V → −1.5 V (first electrochromic layer decoloration → color development) Chronoamperometry and chronocoulometry were measured under the conditions. For the measurement, a potentiostat (model number HZ-5000) manufactured by Hokuto Denko was used. The experimental results are shown in FIGS. 10 and 11 show the chronoamperometry measurement results, and FIGS. 12 and 13 show the chronocoulometry measurement results.

  As shown in FIGS. 10 and 11, when the patterns of the electrochromic layers are arranged opposite to each other, the current becomes zero faster than when the patterns are shifted from each other. It was found that the response time was shortened and the response was excellent. The charges in FIGS. 12 and 13 are caused by coloring → decoloring and decoloring → coloring, and the amount of charge (absolute value) is shifted when the patterns of the electrochromic layers are arranged to face each other. Clearly, it was found that the switching from color development to color erasure and color erasure to color development was quick.

  In addition to the examples, in the comparative example using the gel electrolyte, when the pattern facing type electrochromic element shown in FIG. 5B was formed and the response time was measured, coloring → decoloring and decoloring → The response time required for color development was about 1 to 3 seconds, indicating that the response was almost equivalent.

DESCRIPTION OF SYMBOLS 1 Electrochromic element 2, 3 Transparent electrode layer 5, 7 Electrochromic layer 8 Electrolyte layer 9 Porous layer 10 Electrolytic solution 11 Continuous pore 13 Sealing layer

Claims (8)

In an electrochromic device having a pair of electrode layers facing each other with a gap in the height direction, an electrochromic layer sandwiched between the electrode layers and an electrolyte layer in contact with the electrochromic layer,
The electrolyte layer is formed by impregnating a porous layer with an electrolytic solution, and the porous layer has continuous pores extending from the first surface to the second surface facing in the height direction. An electrochromic device characterized by.   The electrochromic device according to claim 1, wherein the porous layer is made of a material that swells with the electrolytic solution.   The electrochromic device according to claim 2, wherein the porous layer is a silicone rubber sheet.   The electrochromic device according to claim 1, wherein the porous layer is whitened or colored.   The electrochromic device according to any one of claims 1 to 4, wherein white particles or colored particles are taken into the continuous pores.   The electrochromic device according to claim 1, wherein a sealing layer having a height substantially the same as that of the electrolyte layer is provided around the electrolyte layer.   The electrochromic device according to claim 6, wherein the sealing layer is integrally formed with the porous layer as a layer without the continuous pores.   The electrochromic layer formed in the inner surface of each electrode layer which mutually opposes at intervals is mutually opposingly arranged by the said height direction via the said electrolyte layer. Electrochromic element.

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