Electrochromic device

Abstract

The invention relates to an electrochromic device (1) comprising a first layer of electrochromic material (10); a second layer of transparent electrochromic material (11) positioned above the first layer (10); an electrolyte layer (12) arranged between the first (10) and second (11) layers of electrochromic material, characterized in that it comprises at least a first current-conducting layer (13a) in contact with the second layer of electrochromic material (11), in that the second layer of electrochromic material (11) forms an electrode of the electrochromic device (1) and in that the first current-conducting layer (13a) forms a current collector of the device (1) in electrical contact only with the second layer of electrochromic material (11). Figure to be published with the abstract: Fig. 1

Description

Title of the invention: Electrochromic device Technical field

[0001] The invention relates to the technical field of electrochromic devices. State of the art

[0002] An electrochromic device, comparable to an optical battery, is an electrical device capable of modulating its optical properties under the application of an electric field, thus making it possible to obtain a device whose color change or light transmission capacity is easily adjustable.Electrochromic devices can thus be used in applications such as modulating the transmission of light desired for aesthetic reasons, light control or energy efficiency, for example electrochromic windows on residential glazing, in particular to adjust the level of sunlight in a room according to external conditions and the wishes of the users or glazing of motor vehicles as windshields and / or side windows or roof glazing of a car, in order to adjust the level of transparency and in particular to be able to adjust the light rays transmitted to the driver to avoid possible glare of the latter. Electrochromic devices can also be found in applications for electrochromic mirrors, display screens or even data display screens.

[0003] However, in the electrochromic devices already known, these often tend to have a switching speed which is quite slow, that is to say that the change of color is not as rapid and optimal as one might hope for applications of this type of product.

[0004] The invention therefore falls within this context and seeks to resolve all of the aforementioned drawbacks. Thus, the invention seeks to propose an electrochromic device making it possible to improve the speed of color change. Presentation of the invention.

[0005] The subject of the invention is an electrochromic device comprising a first layer of electrochromic material; a second layer of transparent electrochromic material positioned above the first layer; an electrolyte layer arranged between the first and second layers of electrochromic material. The electrochromic device is remarkable in that it comprises at least a first current-conducting layer in contact with the second layer of electrochromic material, in that the second layer of electrochromic material forms an electrode of the electrochromic device and in that the first current-conducting layer of current forms a current collector of the device in electrical contact only with the second layer of electrochromic material.

[0006] In the context of the present invention, the term "layer" is understood as a more or less uniform extent of a substance whose thickness is small relative to its surface area. By way of non-limiting example, it may be provided that each layer is produced during the same step of a method of manufacturing the device according to the invention or that several layers, in particular formed by the same material or the same combination of materials, are produced simultaneously during the same step of a method of manufacturing the device according to the invention.

[0007] In the context of the present invention, the terms "electrochromic material" are understood to mean a material or a combination of materials capable of reversibly changing color and / or transparency in response to an electrical charge applied to this material or this combination of materials. Preferably, the change in color and / or transparency can be carried out when an electrical voltage is applied between the electrodes of the device, creating a migration of ions through the electrolyte layer to react with the electrochromic material according to an oxidation-reduction reaction.

[0008] The first layer of electrochromic material may be adapted to conduct electric current. The first layer of electrochromic material may comprise an electrode. The second layer of electrochromic material is adapted to comprise a conductive electrical charge. The second layer may comprise an electrode. The first layer of electrochromic material may comprise a material distinct from that of the second layer of electrochromic material.

[0009] The second layer of electrochromic material can improve the speed of color change and / or transparency. It is this layer which can either be a transparent electrode or a material which can change color.

[0010] Thus, the electrochromic device can change color or transparency under the influence of an electrical voltage applied between the electrodes. This change in color or transparency can be achieved by electrochemical reactions in the electrochromic materials. It is the electrochromic material that can have the ability to undergo reversible changes in color or transparency in response to electrical stimulation.

[0011] The current-conducting layers may allow the application of an electrical voltage between the electrodes of the device. An electric field may be created across the electrolyte which may cause the reversible or irreversible change in color or transparency, creating the electrochromic effect.

[0012] In this system, the electrolyte can allow the mobility of the ions and thus allow better performance of the electrochromic device. The electrolyte can comprise a substance which can produce ions capable of conducting electricity and moving under the effect of an electric field.

[0013] The current collector may be a component of the electrochromic device used to collect electric current from different sources or elements and direct it to a specific destination. The collector does not directly receive any charge of the same nature as that of the electrolyte layer. The current collector layer may be a carbon layer.

[0014] Advantageously, the second layer of electrochromic material is in full contact with the electrolyte layer.

[0015] Advantageously, the electrochromic device comprises a second current-conducting layer in contact with the first layer of electrochromic material, said first layer of electrochromic material forming an electrode of the electrochromic device.

[0016] The second current-conducting layer is not in physical contact with the first current-conducting layer.

[0017] Each of the first and second layers of electrochromic material may comprise an electrode. One of the layers of electrochromic material may comprise a cathode electrode and the other of the layers of electrochromic material may comprise an anodic counter-electrode.

[0018] Advantageously, the electrochromic device comprises a blocking layer arranged between the first electrochromic layer and the second electrochromic layer and capable of opposing the migration of ions in the electrolyte layer, the blocking layer defining at least one passage through which the ions of the electrolyte layer can circulate freely.

[0019] The blocking layer may comprise a dielectric material. The blocking layer may comprise an outer contour that can define a pattern. The blocking layer may comprise an inner contour delimited by the at least one passage. The inner contour may define a pattern. Thus, by using an alternation between the passages allowing the free circulation of ions and the parts of the blocking layer preventing said circulation of ions, it may be possible to create patterns with the electrochromic device.

[0020] It is the blocking layer which can thus make it possible to display a pattern which was invisible when the electrochromic device is in the passive state and which becomes visible when the electrochromic device is activated by potential difference.

[0021] Advantageously, the first current-conducting layer comprises carbon.

[0022] In one embodiment, the second current-conducting layer may comprise carbon.

[0023] In a particular embodiment, the first current-conducting layer and / or the second current-conducting layer may comprise metal.

[0024] Advantageously, the second electrochromic layer and the electrolyte layer of the electrochromic device are free of inorganic materials.

[0025] In one embodiment, the blocking layer may be free of inorganic materials.

[0026] Advantageously, the first and / or the second electrochromic layer comprises an electrically conductive material.

[0027] The electrically conductive material may, in one embodiment, comprise PEDOT:PSS.

[0028] Advantageously, the electrolyte layer comprises a polymer suitable for crosslinking under UV.

[0029] In one embodiment, the electrolyte layer comprises at least one ionic liquid. In another embodiment, the electrolyte layer may be devoid of ionic liquid.

[0030] In one embodiment, the electrolyte layer may comprise solubilized salts.

[0031] Advantageously, the electrochromic device comprises at least a first encapsulation layer arranged to cover the device.

[0032] In an embodiment comprising a support layer comprising a plastic substrate, the electrochromic device may comprise only the first encapsulation layer.

[0033] In an embodiment comprising a support layer comprising a substrate free of plastic, the electrochromic device may comprise the first encapsulation layer and a second encapsulation layer mounted between said support layer and the first layer of electrochromic material.

[0034] The invention also relates to a method for manufacturing an electrochromic device as described above. The method is remarkable in that it comprises the following steps: deposition of an electrochromic material to form the first electrochromic layer; deposition of an electrolyte material on the first electrochromic layer to form the electrolyte layer; deposition of an electrochromic material on the electrolyte layer to form the second electrochromic layer; deposition of a current-conducting material on only a portion of the second electrochromic layer to form the first current-conducting layer; deposition of a current-conducting material on a portion of the first electrochromic layer to form the second current-conducting layer.

[0035] In the method of manufacturing the electrochromic device, deposition means deposition of the layer, for example by printing.

[0036] The second encapsulation layer may be adapted to cover at least a portion of the substrate. In another embodiment, the second layer may completely cover the substrate.

[0037] The electrochromic material forming the first layer of electrochromic material may be deposited on only a portion of the second encapsulation layer.

[0038] The electrolyte material may be arranged to completely or partially cover the blocking layer and to overlap a portion of the electrochromic layer at the opening of the blocking layer.

[0039] The second electrochromic layer may be arranged to cover the electrolyte layer.

[0040] The current-conducting material of the first current-conducting layer disposed on only a portion of the second electrochromic layer may also cover a portion of the substrate. In an embodiment comprising the second encapsulation layer, said current-conducting material of the first current-conducting layer may cover a portion of said second encapsulation layer.

[0041] The second current-conducting layer may overlap a portion of the second electrochromic layer and a portion of the substrate. In another embodiment comprising the second encapsulation layer, said second current-conducting layer may cover a portion of said second encapsulation layer.

[0042] In one embodiment, the electrochromic device may comprise a support layer which may comprise a substrate. In one embodiment, the substrate may be flexible. In one embodiment, the substrate may comprise paper.

[0043] Advantageously, the electrochromic device comprises a substantially flexible support layer on which the first layer of electrochromic material is positioned.

[0044] The support layer may be a dielectric material. In another embodiment, the support layer may be paper.

[0045] Advantageously, the manufacturing method comprises the following steps: deposition of an encapsulation material to form the second encapsulation layer; deposition of a dielectric material to form the blocking layer; deposition of an encapsulation material to form the first encapsulation layer.

[0046] The dielectric material forming the blocking layer may be arranged to overlap a portion of the first electrochromic layer and a portion of the second encapsulation layer.

[0047] The first encapsulation layer may be adapted to cover at least a portion of the electrochromic device. In another embodiment, the first encapsulation layer may be adapted to completely cover the electrochromic device.

[0048] Advantageously, in the manufacturing process, the first current-conducting layer and the second current-conducting layer are deposited simultaneously.

[0049] The first current-conducting layer and the second current-conducting layer are distinct from each other, i.e. they are not in contact with each other but are printed at the same time. Brief description of the figures.

[0050] Other advantages and characteristics of the present invention are now described with the aid of examples which are purely illustrative and in no way limitative of the scope of the invention, and from the appended drawings, drawings in which the various figures represent:

[0051] [Fig-1] schematically represents a sectional view of an electrochromic device.

[0052] In the following description, elements which are identical, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references. Description of an embodiment.

[0053] [Fig.l] schematically shows a sectional view of an electrochromic device 1 according to one embodiment.

[0054] The electrochromic device 1 described in [Fig.l] is manufactured by using a flexible substrate 17. The substrate 17 comprises paper. The substrate 17 serves as a support for the electrochromic device 1.

[0055] An encapsulation material is deposited on the substrate 17 to form a second encapsulation layer 16. The deposition of the encapsulation material is carried out by printing.

[0056] An electrochromic material is deposited on the second encapsulation layer. 16 to form a first electrochromic layer 10. The deposition of the electrochromic material is carried out by printing. The first layer of electrochromic material 10 covers only a portion of the second encapsulation layer 16. The first electrochromic layer 10 comprises an electrically conductive material and is adapted to conduct electric current. The first electrochromic layer 10 comprises PEDOT:PSS.

[0057] A dielectric material is deposited to form a blocking layer 14. The deposition of the dielectric material is carried out by printing. The blocking layer covers a portion of the first electrochromic layer 10 and a portion of the secondencapsulation layer 16. The blocking layer is arranged between the first electrochromic layer 10 and a second electrochromic layer 11. The blocking layer 14 is capable of opposing the migration of ions in an electrolyte layer 12. The blocking layer 14 defines at least one passage through which the ions of the electrolyte layer 12 can circulate freely. The blocking layer 14 has an outer contour defining a pattern. The blocking layer 14 has an inner contour delimited by at least one passage. The inner contour defines a pattern. Thus, by using an alternation between the passages allowing the free circulation of ions and the parts of the blocking layer 14 preventing said circulation of ions, it is possible to create patterns with the electrochromic device 1.It is the blocking layer 14 which thus makes it possible to display the pattern which is invisible when the electrochromic device 1 is in the passive state and which becomes visible when the electrochromic device 1 is in an activated position. The blocking layer 14 is devoid of inorganic materials.

[0058] An electrolyte material is deposited to form the electrolyte layer 12. The deposition of the electrolyte material is carried out by printing. The electrolyte layer 12 is arranged to cover the blocking layer 14 and to overlap a portion of the first electrochromic layer 10, at the opening of the blocking layer 14. The electrolyte material comprises a substance which produces ions capable of conducting electricity and moving under the effect of the electric current. The electrolyte layer 12 comprises a polymer suitable for crosslinking under UV.

[0059] An electrochromic material is deposited to form the second layer of electrochromic material 11. The deposition of the electrochromic material is carried out by printing. The second layer of electrochromic material 11 is adapted to comprise a conductive electrical charge. The second electrochromic layer 11 comprises an electrode. The second electrochromic layer 11 comprises a transparent electrode. The second electrochromic layer 11 comprises an electrically conductive material and is adapted to conduct the electric current. The second electrochromic layer 11 comprises a conductive polymer.

[0060] A current-conducting material is deposited to form a first current-conducting layer 13a. The first current-conducting layer 13a is arranged to cover only a portion of the second electrochromic layer 11. The first current-conducting layer 13a is arranged to cover a portion of the second encapsulation layer 16. The first current-conducting layer 13a comprises carbon.

[0061] A current-conducting material is deposited to form a second current-conducting layer 13b. The second current-conducting layer 13b is arranged to cover a portion of the first layer of electrochromic material 10, said portion not being covered by the blocking layer 14 and the layer electrolyte 12. The second current-conducting layer 13b covers a portion of the second encapsulation layer 16. The second current-conducting layer 13b is not in physical contact with the first current-conducting layer 13a. The second current-conducting layer 13b comprises carbon.

[0062] The current-conducting material forming the first current-conducting layer 13a and the current-conducting material forming the second current-conducting layer 13b are deposited simultaneously by printing. The first current-conducting layer 13a and the second current-conducting layer 13b are physically distinct from each other, so they are not in contact with each other but are printed at the same time in the manufacturing process of the electrochromic device 1.

[0063] An encapsulation material is deposited to form a first encapsulation layer 15. The first encapsulation layer 15 is arranged to cover at least a portion of the electrochromic device 1.

[0064] The foregoing description clearly explains how the invention achieves the objectives it sets for itself, namely to provide an electrochromic device for improving the color change speed, by providing an electrochromic device comprising a first layer of electrochromic material; a second layer of transparent electrochromic material positioned above the first layer; an electrolyte layer arranged between the first and second layers of electrochromic material and comprising at least a first current-conducting layer in contact with the second layer of electrochromic material, in that the second layer of electrochromic material forms an electrode of the electrochromic device and in that the first current-conducting layer forms a current collector of the device in electrical contact only with the second layer of electrochromic material.

[0065] In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically effective combination of these means. In particular, it may be envisaged:

[0066] - a support layer of the electrochromic device, a substrate comprising a dielectric material;

[0067] - a support layer comprising a plastic substrate, in this embodiment, the electrochromic device only has the first encapsulation layer;

[0068] - the second current-conducting layer 13b may overlap a portion of the second electrochromic layer 11 and a portion of the substrate 17;

[0069] - the electrolyte layer 12 may be devoid of ionic liquid;

[0070] - the electrolyte layer 12 may comprise solubilized salts;

[0071] - the first 10 and the second 11 layers of electrochromic material can include distinct materials;

[0072] - the second electrochromic layer 11 comprises a material which can change color ;

[0073] - the first current-conducting layer 13a may comprise metal;

[0074] - the second current-conducting layer 13b may comprise metal.

Claims

Claims

1. Electrochromic device (1) comprising: - A first layer of electrochromic material (10); - A second layer of transparent electrochromic material (11) positioned above the first layer (10); - An electrolyte layer (12) arranged between the first (10) and second (11) layers of electrochromic material; characterized in that it comprises at least a first current-conducting layer (13a) in contact with the second layer of electrochromic material (11), in that the second layer of electrochromic material (11) forms an electrode of the electrochromic device (1) and in that the first current-conducting layer (13a) forms a current collector of the device (1) in electrical contact only with the second layer of electrochromic material (11).

2. Electrochromic device (1) according to claim 1 characterized in that the second layer of electrochromic material (11) is in full contact with the electrolyte layer (12).

3. Electrochromic device (1) according to one of the preceding claims, characterized in that it comprises a second current-conducting layer (13b) in contact with the first layer of electrochromic material (10), said first layer of electrochromic material (10) forming an electrode of the electrochromic device (1).

4. Electrochromic device (1) according to one of the preceding claims, characterized in that it comprises a blocking layer (14) arranged between the first electrochromic layer (10) and the second electrochromic layer (11) and capable of opposing the migration of ions in the electrolyte layer (12), the blocking layer (14) defining at least one passage through which the ions of the electrolyte layer (12) can circulate freely.

5. Electrochromic device (1) according to one of the preceding claims, characterized in that the second electrochromic layer (11) and the electrolyte layer (12) of the electrochromic device (1) are free of inorganic materials.

6. Electrochromic device (1) according to one of the preceding claims, characterized in that the first (10) and / or the second electrochromic layer (11) comprises an electrically conductive material.

7. Electrochromic device (1) according to one of the preceding claims, characterized in that the electrolyte layer (12) comprises a polymer suitable for crosslinking under UV.

8. Electrochromic device (1) according to one of the preceding claims, characterized in that it comprises at least one first encapsulation layer (15) arranged to cover the device (1).

9. Method for manufacturing an electrochromic device (1) according to one of the preceding claims taken in combination with claim 3, characterized in that it comprises the following steps: - Deposition of an electrochromic material to form the first electrochromic layer (10); - Deposition of an electrolyte material on the first electrochromic layer (10) to form the electrolyte layer (12); - Deposition of an electrochromic material on the electrolyte layer (12) to form the second electrochromic layer (11); - Deposition of a current-conducting material on only a portion of the second electrochromic layer (11) to form the first current-conducting layer (13a); - Deposition of a current-conducting material on a portion of the first electrochromic layer (10) to form the second current-conducting layer (13b).

10. Manufacturing method according to the preceding claim taken in combination with claim 8, characterized in that it comprises the following steps: - Deposition of an encapsulation material to form a second encapsulation layer (16); - Deposition of a dielectric material to form the blocking layer (14); - Deposition of an encapsulation material to form the first encapsulation layer (15).

11. Manufacturing method according to the preceding claim, characterized in that the first current-conducting layer (13a) and the second current-conducting layer (13b) are deposited simultaneously.

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