EP1078299A1

EP1078299A1 - Electrochemical device, such as an electrically controlled system with variable optical and/or energy properties

Info

Publication number: EP1078299A1
Application number: EP00910992A
Authority: EP
Inventors: Claude Morin; Fabien Beteille; Jean-Christophe Giron
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Sage Electrochromics Inc
Priority date: 1999-03-19
Filing date: 2000-03-17
Publication date: 2001-02-28
Also published as: JP4851009B2; AU3300500A; WO2000057243A1; FR2791147B1; PL344188A1; US7012728B2; FR2791147A1; US20060033978A1; KR20010043668A; US7265889B2; KR100715331B1; JP2002540459A; US6747779B1; PL207628B1; CA2332622A1; AU774653B2; US20040191618A1

Abstract

The invention concerns an electrochemical device, in particular an electrically controlled system with variable optical and/or energy properties, comprising at least a substrate provided with a stack of functional layers including at least one electroconductive layer A based on metal oxide(s) and at least an electrochemically active layer F. Said layer A forms part of a multicomponent electrode E associating with the layer A at least a material B more conductive than the former and/or at least a network C of conductor wires or conduction bands. The invention also concerns its uses, in particular in glazing.

Description

ELECTROCHEMICAL DEVICE, SYSTEM TYPE

ELECTROCOMMANDABLE WITH PROPERTIES

VARIABLE OPTICS AND / OR ENERGY

The invention relates to electrochemical devices, in particular of the type comprising those comprising at least one carrier substrate provided with a stack of functional layers including at least one electroconductive layer and at least one electrochemically active layer. More particularly targeted are electrically controllable systems with variable optical and / or energy properties, in applications to glazing or mirrors.

There is indeed an increasing demand for so-called “intelligent” glazing, the properties of which can be modulated.

Thus, thermally, the glazing whose transmission / absorption can be modulated in at least part of the solar spectrum make it possible to control the solar contribution inside the rooms or compartments / compartments when they are mounted in exterior glazing of building or windows of means of transport such as cars, trains, planes, etc., and thus avoid excessive heating of these in case of strong sunshine. On the optical level, they allow a control of the degree of vision, which makes it possible to avoid the glare when they are assembled in external windows in the event of strong sunshine. They can also have a particularly interesting shutter effect, both as exterior glazing as if they are used in interior glazing, for example to equip interior partitions between rooms (offices in a building), or to insulate compartments in trains or planes for example.

Many other applications exist: one can for example use glazing with variable light transmission / reflection to make mirrors, which can be darkened if necessary to avoid dazzling the driver of the car. They can also be used for road signs, for any display panel, for example in order to make the drawing / message appear only intermittently to better attract attention.

A particularly interesting application of systems with variable light absorption concerns display screens, in particular all those equipping televisions and computer equipment. Indeed, this type of glazing makes it possible to improve the contrast of the image, in particular by taking into account the ambient brightness.

The interest that such glazing can arouse justifies that many systems have already been studied.

Two systems are of particular interest to the invention: viologenic systems and electrochromic systems. Viologenic systems make it possible to modulate the transmission or absorption, essentially in the visible domain, of the glazings which incorporate them. They generally comprise a single “active layer” based on polymer, gel or liquid containing both an active material called cathodic like viologenic molecules, and an active material called anodic like dimethylferrocene or phenazines. Examples are described in patents EP-0 612 826 and US-5 239 406.

Electrochromic systems, in a known manner, comprise a layer of an electrochromic material capable of reversibly and simultaneously inserting ions and electrons and whose oxidation states corresponding to the inserted and uninserted states are of distinct coloration, one of the states exhibiting one light transmission higher than the other, the insertion or removal reaction being controlled by an adequate power supply. The electrochromic material, usually based on tungsten oxide, must thus be brought into contact with an electron source such as a transparent electroconductive layer and with a source of ions (cations or anions) such as 'an ion conductive electrolyte.

Furthermore, it is known that to ensure at least one hundred switching operations, it must be associated with the layer of material. electrochromic a counter-electrode also capable of reversibly inserting cations, symmetrically with respect to the layer of electrochromic material, so that, macroscopically, the electrolyte appears as a simple medium for ions. The counter-electrode must consist of either a neutral layer in coloring, or at least transparent or little colored when the electrochromic layer is in the colored state. Since tungsten oxide is a cathodic electrochromic material, that is to say that its colored state corresponds to the most reduced state, an anodic electrochromic material based on nickel oxide or iridium oxide is generally used for the counter electrode. It has also been proposed to use an optically neutral material in the oxidation states concerned, such as for example cerium oxide or organic materials such as electronic conductive polymers (poly aniline, etc.) or prussian blue. The description of such systems can be found for example in European patents EP-0 338 876, EP-0 408 427, EP-0 575 207 and EP-0 628 849.

Currently, these systems can be classified into two categories, depending on the type of electrolyte they use: ** ^• either the electrolyte is in the form of a polymer or a gel, for example a conduction polymer proton such as those described in European patents EP-0 253 713 and EP-0 670 346, or a polymer with lithium ion conduction such as those described in patents EP-0 382 623, EP-0 518 754 or EP -0 532 408, * • ^• either the electrolyte is a mineral layer, ionic conductor but electronically insulating, we then speak of “all-solid” electrochromic systems. For the description of an “all-solid” electrochromic system, reference may be made to European patent applications EP-0 867 752 and EP-0 831 360. Other types of electrochromic systems exist. Mention may thus be made of “any polymer” electrochromic systems, or two electroconductive layers are arranged on either side of a stack comprising a cathodic-colored polymer, an ionically conductive electronic insulating polymer (of H + or Li ^{+ in} particular) , and finally an anodically colored polymer (such as polyaniline or polypyrrole).

Finally, there are also “active” systems within the meaning of the invention which combine viologenic materials and electrochromic materials, for example having the conductive electrode / mineral layer or polymer sequence with electrochromic properties / layers (liquid, gel, polymer) with viologenic properties / conductive electrode.

These systems with reversible insertion material (s) are particularly interesting in the sense that they make it possible to modulate the absorption in a wider wavelength range than the viologenic systems: they can absorb in a variable manner not only in the visible, but also, in particular, in the infrared, which can give them an effective optical and / or thermal role.

A common point between these different systems hereinafter referred to as “active” systems is that their transmission / absorption state is controlled by imposing a potential difference at their terminals generally constituted by two electroconductive layers enclosing the layer or layers electrochemically active. When these systems are part of “active” glazing, transparency is preferred for these electroconductive layers (or at least one of them, if the other is chosen such that it reflects in the visible for application to mirrors). To choose the nature of these electroconductive layers, a material is required that is both sufficiently conductive and sufficiently transparent in the thickness ranges that are usually encountered in the field of thin layers. The choice is usually made on a doped metal oxide material, such as fluorine-doped tin oxide (Snθ2: F) or tin-doped indium oxide (ITO), which can be deposit on different substrates hot (in particular by pyrolysis on glass like the CVD technique) or cold (vacuum techniques of the sputtering type).

However, it has been found that in thicknesses where they remain transparent, the layers based on this type of material are not fully satisfactory, even if they allow active systems to function. Insufficiently conductive, they would contribute to increasing the response time of active systems when the appropriate electrical power is applied to their terminals to cause them to change the transmission / absorption state (state hereinafter referred to as " coloration ”, even if the modification of the properties also takes place outside the visible range, for more simplicity).

Besides therefore the fact that they would slow down the speed of switching of the systems, (the “switching” or the “response time” being the period of time necessary for the whole active system to have changed state of coloring), they would contribute to create an edge phenomenon, that is to say the fact that the system changes its state in a non-uniform manner in its surface, with a change in "coloring" within the meaning of the invention which is almost immediate in the zones close to the current leads supplying the electroconductive layers, arranged at the periphery of the systems, and which progressively propagates towards the center of the surface of the active systems. However, in certain applications, in particular glazing for the building or the automobile, the end user generally wishes a response time as rapid as possible, and may prefer, moreover, a uniform gradual change in coloring over the entire surface of the active glazing.

The object of the invention is therefore to improve the performance of the electrically conductive layers of the “active” systems defined below, in particular “active” glazing incorporating the latter, an improvement aimed in particular at their electrical conductivity combined with their optical properties.

The invention firstly relates to an electrochemical device, in particular an electrically controllable system with variable energy and / or optical properties, comprising at least one carrier substrate provided with a stack of functional layers including at least one electrically conductive layer A based of metal oxide (s) and at least one electrochemically active layer F. The invention consists in that said layer A forms part of a “multi-component” electrode E associating with layer A at least one material B more electrically conductive than it and / or at least one network C of conductive wires or conductive strips. For the purposes of the invention, the term "more conductive" includes a material B which, in the form of a layer, has a resistance by "square

R "square less than that of layer A. Within the meaning of the invention always,

"Association" means that the elements concerned are electrically connected to each other, either by direct contact, or by means of elements / conductive layers (trices) also.

Indeed, increasing the thickness of the layer A to amplify the conductivity (which amounts to lowering its resistance per square) is a solution which has limits: first in terms of cost, time of manufacture of the layer in question, then in terms of optical appearance: from a certain thickness, the layers of this type begin to absorb in the visible. However, for active glazing very particularly, depending on their applications, it is generally sought to ensure maximum light transmission in the "non-colored" state. The solution according to the invention then consisted in developing two variants, alternative or cumulative, to reconcile conductivity and transparency.

The material B defined above can be associated with the layer A in two different ways: according to a first variant, it can be in the form of at least one layer associated with A, in electrical contact with the latter.

The characteristics and thicknesses of the layers can then be adjusted as best as possible so that, overall, the multi-component electrode which combines them has the required levels of transparency and resistance per square. A second variant consists in incorporating the material B into the layer A, in particular in the form of fibers, of particles of small dimensions. It is thus possible to use a layer A based on doped oxide, for example Snθ2: F, which is deposited in known manner by liquid pyrolysis from suitable organometallic precursors, by adding to the liquid phase containing these precursors metallic fibers or particles, or by spraying them onto the surface of the substrate at the same time as the liquid phase (for example fibers with a diameter of the order of 10 μm and a length of around 1 mm). The fibers are found in the layer with a random distribution, "percolating" on the surface of the substrate thus coated. In this case, the doped metal oxide of layer A also fulfills the function of fixing the metal fibers B.

The third variant consists in combining the type layer (s)

A with a network of conductive elements, in particular based on metal intrinsically more conductive than the type A material. In fact, as detailed below, this network can be made up of linear elements visible to the eye in the immediate vicinity , but discreet enough to be compatible with most of the applications targeted in glazing for buildings or vehicles. It is therefore advantageous to configure the dimensioning and the arrangement of these elements so that they are as visible as possible. Generally, it can be achieved that this network is almost indistinguishable, at least when the system is in the colored state.

Note that, in the same active system, these different variants are alternative or cumulative.

The common point between these variants is that the additional conductive element, namely the material B or the network C, makes it possible to cross the overall electrode thus constituted a threshold of conductivity such that one achieves that the the entire electrode is at the same potential difference almost at the same time, as soon as the system is powered up, which significantly reduces the switching time and decreases or even eliminates the phenomenon of “coloring front” mentioned above. And this very interesting technical result is not obtained at the expense of the optical quality of the system: ** ^• either this additional element is itself little or not absorbing in the visible, because being transparent, it does not significantly modify the appearance of the glazing or the transmission / absorption range in which it can vary under the effect of an electrical supply (type B layer), ** - either this additional element is sufficiently discreet not to disturb the overall aesthetics of the active system (type C network).

Advantageously, the layer (s) A is (are) based on metal oxide made conductive by doping. It can be, in particular doped tin oxide, in particular with a halogen of the fluorine type (Snθ2: F) or with antimony SnO ₂ : Sb, or zinc oxide doped for example with aluminum (ZnO: A1), or tin (ZnO: Sn), or fluorine

(ZnO: F), or indium (ZnO: In). It can also be indium oxide doped with tin such as ITO.

Advantageously, the layer (s) B, according to the first variant, is (are) essentially metallic (s), in particular based on at least one noble metal or based on an alloy containing a noble metal of the silver Ag type. or Au gold or copper Cu or aluminum Al. Preferably, a layer based on a silver alloy with another metal such as nickel or titanium is chosen. Indeed, the layer is thus much less sensitive to oxidation, especially when it is in electrical contact with layers of electrochromic materials of an "all-solid" system. Gold is also a material less sensitive to oxidation than pure silver, it is however less satisfactory on the optical level, it is less neutral in transmission. The combination of a type A layer and a type B layer is particularly advantageous: as already seen, it makes it possible to sufficiently amplify the electrical conductivity of type A layers with thin layers B therefore not too disturbing optically . It is also a new means for incorporating B layers, in particular silver layers, into electrodes, the use of which has hitherto posed the problem of their protection against attack, in particular with regard to oxidizing agents. Thus, we will be able to use the type A layers to “protect” the type B layers, in particular with respect to oxidation / degradation, the A layers having a dual function of protection and electrical conductor, or even a triple function, also with an optical function this time when the thicknesses of the type A layers are adjusted as a function of those of the type B layers to best optimize the optical appearance of the assembly by interferential interaction between these various layers . It is thus possible to reduce, for example, the light reflection induced by layer B.

As mentioned above, the characteristics of the layers incorporated in the multi-component electrodes of the invention are chosen so that they are essentially transparent in the visible. According to the second variant, the small elements of the fiber, particle, grain type which are incorporated into the layer may be of the same metal as that evoked by the layer B: Ag, Au, Cu, Al, or else based on Steel, of alloy with Ni, Cr Advantageously, the network C according to the third variant of the invention comprises, according to a first embodiment, a plurality of conductive strips, in particular essentially parallel to each other and obtained by screen printing from a pasty suspension of silver-type metal and a low-melting frit in an organic type binder. The serigraphy can be carried out on a carrier substrate of the glass type, it can then be covered with at least one electroconductive layer A in order to constitute an electrode according to the invention. A variant consists in doing the opposite operation, namely depositing the network C on the electrically conductive layer A. The technique of deposition by screen printing on glass is in itself known for depositing conductive networks for other applications, and very particularly for constituting heating systems for vehicle glazing, to allow demisting or defrosting using the Joule effect. For more details on this technique, one can refer, for example, to patents FR-1 464 585 and EP-0 785 700. The sought-after function being here different, it is up to the specialist to determine the bandwidth and the most appropriate spacing between bands to have the best compromise between conductivity and aesthetics (for example a band width of 0.1 to 0.5 mm and a spacing between bands of 1 to 5 mm). According to a second embodiment, the network C comprises a plurality of conductive wires of essentially metallic type, preferably deposited on the surface of a sheet based on a polymer of thermoplastic type. As for the first embodiment, it is known by known techniques to deposit conductive wires on films, for example of polyvinyl butyral, which are associated by laminating with glasses to form laminated glazings, the network having a defogging function / defrost by Joule effect. We can therefore adapt these techniques, possibly by adjusting the configuration, spacing and sizing of the wires, to design a network that we have just plating, associated with the thermoplastic film, with the type A layer itself disposed on the rest of the stack of functional layers of the active system, in particular by a lamination technique. For more details on the technique for depositing these threads, reference may be made, in particular, to patents EP-0 785 700, EP-0 553 025, EP-0 506 521 and

EP-0 496 669. The wires can be laid in a wavy form or in a straight line. Schematically, the method consists in using a heated pressure roller to press the wire on the surface of the thermoplastic film, a pressure roller supplied with wire from a supply reel by means of a wire guide device.

According to another embodiment, the network C can be taken in a broader sense, and in particular be two-dimensional, in the form of fabric, net, veil obtained by weaving or knitting, sufficiently fine and / or of sufficiently large mesh size to do not obstruct visibility. It may also involve introducing this type of material between the sheet based on thermoplastic polymer which is used in particular for laminating the system and the type A layer.

This type of flexible material can preferably be obtained from metallic wires, in particular with a diameter of between 10 μm and 100 μm. The size of the stitches, the spacing of the knitting, the way in which the weaving is done can be modulated as appropriate. Thus, wires of diameter 15 to 25 μm are preferred, with a knitting structure and inter-mesh spacings of the order of 1 to 3 mm.

The "network" also includes metallic layers sufficiently thick to greatly reduce light transmission, and even to be opaque, and which undergo treatments in order to make them discontinuous. It may be an etching treatment of a metal layer deposited by sputtering, the etching can be carried out by laser in order to leave “threads” (for example 0.3 mm wide and spaced from each other 1.5 mm) or a two-dimensional grid. The layer metal can be stainless steel, copper, silver copper, aluminum, gold in particular.

The metallic layer can also be treated by piercing it with regularly distributed orifices. This metallic layer can also be replaced by a perforated metal sheet inserted between the stack of the active system and the laminating interlayer (sheet thicker than a layer, for example with a thickness of 10 to 100 μm).

We can also adapt the screen printing technology described above, when the substrate is sufficiently rigid as glass, by making shallow scratches on the surface of the glass by etching, scratches in the form of parallel lines that are just filled with the screen printing paste, which leads to a particularly discreet and conducting screen printing network at the same time. Advantageously, provision can be made for the two-dimensional grating C of the grid, fabric type, even if it is self-supporting, to be able to be encrusted on the surface of the film of thermoplastic polymer used for laminating the glazing. It can be pre-encrusted, like the lead wires mentioned above. It can also be embedded in the film during the leafing.

Rather than screen printing conductive wires, one can choose to deposit these wires, for example in tungsten, on substrates already optionally provided with a conductive layer of the doped metal oxide type, and to maintain them at the periphery of the glazing with an adhesive. double-sided suitable can also act as a seal.

According to a preferred embodiment of the first variant according to the invention, the multi-component electrode comprises at least one layer A and at least one layer B in electrical contact, at least one of them being possibly in contact with at least one layer D of dielectric material, the set of layers A, B and D superimposed preferably forming a stack of layers in interferential interaction. In fact, we can find here stacks of layers quite similar to those used as a low-emissivity / sunscreen stack for building or vehicle glazing, these schematically presenting stacks of the type: dielectric coating ® / silver / dielectric coating (D with optionally at the Ag / dielectric interface a thin layer of protective metal. The dielectric coating can be a layer or a superposition of layers based on metal oxide (Snθ2, ZnO, ΗO2, Siθ2, Ta2θδ, Nb2θδ, ...) or of oxynitride or silicon nitride (SiON, Si3N ₄ ) or mixture. Reference may be made, for example, to the stacks described in patents EP-0 611 213, EP-0 678 484 and EP-0 718 200, or else those fitted to the glazing sold under the name of the "Planitherm" range by Saint- Gobain Glazing. Here, their application is diverted, and it is therefore necessary to adapt these stacks, one or more layers of conductive doped oxide (type A) replacing one and / or the other of the dielectric coatings ® and (D mentioned above. Electrically insulating layers must not be interposed between the superposition of conductive layers and the rest of the active layers of the system. However, nothing prevents adding to conductive stacks of the type

(layer A / layer B) or (layer A / layer B / layer A) dielectric layers, insulating, on the opposite side, from the rest of the functional layers, on the side facing the carrier substrate for example. It is thus possible to have stacks of the type: substrate / dielectric D / layer B (type Ag) / layer A (type ITO) / rest of the functional stack of active system.

These layers D then fulfill an optical and / or anchoring function of the type B layers to the substrate and / or fulfill a barrier function to the migration of species originating from the substrate (for example alkalis originating from glass). As mentioned above, the dielectric materials can be in the form of oxide, oxycarbide or oxynitride of metal or silicon or be based on silicon nitride.

Examples of this type of electrode are for example ITO / Ag / ITO or Ag / ITO or dielectric / Ag / ITO with possible interposition of thin layers of partially oxidized metal at the Ag / ITO interface, the second layer of ITO protecting the silver layer, while participating in the electrical conductivity of the assembly.

The multi-component electrodes according to the invention are provided with appropriate current leads, in a manner known in the art, in particular in the form of foils or metal braids.

As mentioned above, the invention applies in particular to an electrochromic system with at least one carrier substrate and a stack of functional layers comprising at least, successively, a first electroconductive layer, an electrochemically active layer capable of reversibly inserting ions such as H ⁺ , Li ⁺ , OH "of the anodic or respectively cathodic electrochromic material type, an electrolyte layer, a second electrochemically active layer capable of '' reversibly insert ions such as H ⁺ , Li ⁺ , OH- of the cathodic or respectively anodic electrochromic material type, and a second electroconductive layer, with at least one of the electroconductive layers in the form of an oxide-based layer A ( s) metallic (s) and forming part of a multicomponent electrode E.

It also applies to any viologen system, with at least one carrier substrate and a stack of functional layers comprising at least successively a first electroconductive layer, a film with viologenic properties in the form of a polymer, a gel or of a suspension in liquid medium, a second electroconductive layer, with at least one of the two electroconductive layers of type A based on metal oxide (s) and forming part of a multi-component electrode E.

The invention thus relates to all types of “active” systems described in the preamble to the present application.

Advantageously according to the invention, the stack of functional layers is arranged between two substrates, each of which can be rigid, of the glass or rigid polymer type such as polycarbonate or PMMA (polymethyl methacrylate), semi-rigid, or flexible. of the PET (polyethylene terephthalate) type, preferably all being transparent. They can also be absorbent or not.

The invention also relates to glazing incorporating the active device / system described above, said device using as carrier substrate at least one of the rigid substrates constituting the glazing and / or at least one flexible substrate associated by lamination with one of the rigid substrates constituting said glazing.

The invention also relates to the use of the device and of the glazing described above for making glazing for buildings, in particular external glazing of internal partition or of glass door, or roofs, glazing fitted to internal partitions or windows or roofs of means of transport of the train, airplane, car, boat type, display screen glazing type of computer or television screen, touch screen, glasses, camera lenses or solar panel protections.

The invention also relates to the use of the device described above for making electrochemical energy storage devices of the battery, fuel cell, and the batteries and cells themselves. Indeed, it is very particularly advantageous, for an application to batteries, to use the variant of the invention consisting in using an electrode comprising a perforated metal sheet or metal grid. As the batteries are often produced on fairly fine plastic substrates (of the PET type of around 30 μm), the conductive layers, if they are folded, risk losing their electrical continuity. A thicker metallic “grid” allows to better guarantee this continuity.

Other details and advantageous characteristics of the invention appear from the description given below of various nonlimiting embodiments, with reference to the appended drawings which represent:

Gl figure 1: a viologen glazing according to the invention

D FIG. 2: a first “all-solid” type electrochromic glazing according to the invention,

CI Figure 3: the optical and electrical characteristics of the glazing according to Figure 2, or Figure 4: a second electrochromic glazing type "all-solid" according to the invention.

All the figures are very schematic in order to facilitate reading and do not necessarily respect the scale between the different elements that they represent. EXAMPLE 1

FIGS. 1 a and 1 b represent a viologen system in cross section using an “active” layer 3 based on polymer of the type of that described in the aforementioned patent application EP-0 612 826, disposed between two substrates of clear silica-soda-lime glass 1, 5 4 mm thick, (Figure lb is a sectional view perpendicular to Figure la).

The two substrates 1, 5, each previously covered with a layer 2, 4 in Snθ2: F deposited in a known manner by CVD, were then each provided with a network 6, 7 of conductive strips from a silver by a well-known screen printing technique. The conductive strips have a width of 0.3 mm, are essentially parallel to each other and separated from each other by a distance of about 2 mm. A peripheral seal 8 seals the system.

There are thus two multi-component electrodes associating a screen-printed conductive network and a layer of doped oxide. The layers of SnO2: F can be replaced by a layer of ITO or SnO2: Sb for example, and have a thickness of approximately 400 nm. Note that by also adding a screen-printed network amplifying the conductivity of the electrode, we can allow ourselves to deposit lower thicknesses of conductive layers while retaining the advantage of the invention, namely a reduction in the phenomenon of coloring front and less switching time. Reducing the layer thicknesses of Snθ2: F (or ITO) thus significantly reduces the cost of active glazing. The current leads are formed by a screen printing perpendicular to the screen printed conductive strips, parallel and equidistant from 2 mm. EXAMPLE 2 FIG. 2 represents an embodiment of electrochromic glazing according to the invention: it is an electrochromic glazing with laminated structure with two glasses, in a configuration suitable for example for using as auto roof glazing : two clear glasses 21, 22 are shown, an electrochromic functional system 23 of the “all-solid” type consisting of the following stack of functional layers, and a PU polyurethane sheet 24 (the PU sheet can be replaced by a sheet ethylene vinyl acetate EVA or polyvinyl butyral PVB): * • ^• a first electroconductive layer 25 in SnO ₂ : F of 400 nm deposited by CVD on glass 22,

** ^• a first layer 26 of anodic electrochromic material in iridium oxide (hydrated) IrO _x H _y of 40 nm, (it can be replaced by a layer in hydrated nickel oxide), ** ^• a layer 27 in oxide 100 nm tungsten,

** ^• a second layer 28 of hydrated tantalum oxide of 100 nm,

** ^• a second layer 29 of cathodic electrochromic material based on tungsten oxide HxWOβ of 370 nm,

** ^• a second layer 30 of 50 nm ITO. The glass 22 / functional system 23 assembly is then laminated to the glass 21 by means of the sheet 24 made of PU at least 1.24 mm thick which has been functionalized by depositing a network 31 of parallel metallic wires between them and linear. (It can also be an EVA or PVB sheet, as said above, for example with a thickness of the order of 0.76 mm).

The network is deposited in a known manner by the method described in the patents mentioned above. The current leads are, in known manner, two foils arranged on the opposite edges of the sheet 24 of PU, applied using a soldering iron. It can for example also be braids of metal wires. The electrical contact between these current leads (not shown) and the underlying electroconductive layer is obtained by pressure, during lamination.

The glazing therefore uses a standard electrode on the glass 22, namely a monolayer of Snθ2: F (or ITO for example) and a second electrode according to the invention associating an electroconductive layer of ITO with a network of metallic wires. As in example 1, this configuration makes it possible to use layers of ITO on the side of the PU film thinner than what would be necessary in the absence of the conductive network 31. This network is for example made up of linear parallel wires , made of tungsten or copper, possibly covered with graphite, with an average diameter of 25 μm (for example between 10 and 50 μm). Each line is spaced from the adjacent line by a distance of 2 mm (for example between 1 and 5 mm). This dimensioning is appropriate so that the network, although visible from very close, remains very discreet and even indistinguishable in the colored state, sufficient aesthetic requirement in the context of auto roof glazing.

FIG. 3 gives indications on the optical and electrical behavior of a glazing according to this example, of dimensions 35 × 35 cm ² . Graph 3 characterizes the optical appearance and the electrical behavior of the glazing during switching. The abscissa corresponds to the time T expressed in seconds and the ordinate (left) to the light transmission value TL expressed in% and to the right to the intensity i in mA at the terminals of the glazing. Curve C1 corresponds to the modification TL at the edge of the glazing, and curve C2 corresponds to the modification of TL at the center of the glazing. We can verify that these two curves are (almost) superimposed, which proves the absence or almost absence of coloring front. Curve C3 shows the evolution of the intensity i of the current. EXAMPLE 3 FIG. 4 represents another variant of electrochromic glazing

"All-solid" according to the invention. We find, as in FIG. 2 and in Example 2, two glasses 21, 22 associated by lamination using a film 24 made of PU (or PVB: polyvinyl butyral), the layer 26 of anodic electrochromic material, the layer 29 of cathode electrochromic material separated by layers 27, 28, forming the electrolyte. On the other hand, the electrode 25 ′ placed on the glass 22 now consists of a stack of layers comprising a layer 25 (a) of Sn 2 of 34 nm, surmounted by a layer 25 (b) of silver of 10 nm, itself topped with a layer 25 (c) of 50 nm ITO. This tri-layer is obtained by sputtering assisted by magnetic field, in a known manner. Optionally, the silver layer 25 (b) is provided with a thin metal layer 25 (d) intended to protect it during the deposition of the layer 25 (c) in ITO, when the latter is deposited in reactive mode in presence of oxygen. There is thus a stack made very conductive by the presence of the layer of Ag, of which the light reflection is lowered thanks to the layer of Snθ2 underlying and to the layer of ITO which surmounts it, which serve as anti-reflective layers, by an appropriate choice of their thicknesses. Note that here it is necessary that the layer 25 (c) on the silver is conductive, to ensure energization of the rest of the functional layers of the system, which is not necessary for layer 25 (a) under silver, which essentially has an optical role and which is an insulating dielectric. We can of course plan to replace it (totally or partially) with TITO or Snθ2: F to keep it its optical role while further enhancing the conductivity of all layers 25 (a), 25 (b), 25 (c) of the multi-component electrode.

The second electrode 30 ′ is also a multilayer stack, for example deposited by sputtering and composed of a first layer 30 (a) of ITO of 50 nm, of a second layer 30 (b) of silver of 10 nm and finally a third layer 30 (c) made of 34 nm ITO. Here, it is preferable that the layer 30 (a) and the layer 30 (c) are conductive, although they fulfill the same optical role with respect to the layer of Ag 31 (a) as the layers 25 (a) and 25 (c) with respect to the silver layer 25 (b), because it is simpler to end the stack with a conductive layer in order to affix the connection elements there, which are here metallic foils arranged on the polymer sheet serving as a laminating interlayer.

Before the invention, such a system operated with a first layer of ITO (glass side 21) of 150 nm and a second layer of ITO (PU side 24) of 300 nm. It can therefore be seen that the invention makes it possible to use layers of ITO or SnO2: F which are much thinner, which has a non-negligible impact on the cost of the final glazing. The invention also makes it possible to use layers of Ag, which are very efficient electrically, without having the known drawbacks thereof (very reflective optical appearance, certain brittleness, etc.).

Claims

1. Electrochemical device, in particular electrocontrollable system with variable optical and / or energetic properties, comprising at least one carrier substrate provided with a stack of functional layers including at least one electroconductive layer A based on metal oxide (s) and at least one electrochemically active layer F, characterized in that said layer A forms part of a multi-component electrode E associating with layer A at least one material B more conductive than it and / or at least one network C of conductive wires or conductive strips.

2. Device according to claim 1, characterized in that the material B is in the form of at least one layer associated with the layer A, in electrical contact with it.

3. Device according to claim 1, characterized in that the material B is incorporated in the layer A, in particular in the form of fibers, of particles.

4. Device according to one of the preceding claims, characterized in that the layer (s) A is (are) based on doped metal oxides chosen from at least one of the following doped oxides: doped tin oxide , especially fluorine or antimony, doped zinc oxide, especially aluminum, tin, fluorine, doped indium oxide, especially ITO tin.

5. Device according to one of the preceding claims, characterized in that the material B is essentially metallic, in particular based on metals or their alloys such as Ag, Au, Cu, Al, Ag alloys with another metal in particular nickel or titanium.

6. Device according to one of the preceding claims, characterized in that said multi-component electrode E is essentially transparent in the visible.

7. Device according to one of the preceding claims, characterized in that said network C comprises a plurality of conductive strips, in particular essentially parallel to each other, obtained by screen printing from a pasty suspension of silver-type metal and a low-melting frit in an organic type binder.

8. Device according to claim 7, characterized in that the network C is screen printed on the glass-type carrier substrate and then covered with at least one electroconductive layer A in order to constitute an electrode E or is deposited on the electroconductive layer A covering the carrier substrate.

9. Device according to one of claims 1 to 5, characterized in that the network C comprises a plurality of conductive wires in the form of essentially metallic wires deposited on the surface of a sheet based on polymer of the thermoplastic type.

10. Device according to one of claims 1 to 5, characterized in that the network C is based on a fabric, net, metallic veil, in particular obtained from metallic wires with a diameter between 10 and 100 μm, and preferably deposited on the surface of a sheet based on a thermoplastic type polymer.

1 1. Device according to one of claims 1 to 5, characterized in that the network C is obtained by etching or drilling a metal layer or a metal sheet.

12. Device according to one of the preceding claims, characterized in that the multi-component electrode E comprises at least one layer A and at least one layer B in electrical contact, at least one of these layers being possibly in contact with at least one layer D of dielectric material, all of the layers A, B and D preferably forming a stack of layers in interferential interaction.

13. Device according to claim 12, characterized in that the layer (s) D have an optical function and / or anchoring of the other layers B to the carrier substrate and / or a barrier function to the migration of species coming from glass of the alkaline type, in particular in the form of metal, silicon oxycarbide or oxynitride or silicon nitride.

14. Device according to one of the preceding claims, characterized in that the electrode (s) E multi-component (s) comprises (include) the sequence ITO / Ag / ITO or Ag / ITO with possible interposition of thin layers partially oxidized metal to the Ag / ITO interface.

15. Device according to one of the preceding claims, characterized in that the multi-component electrode (s) E is (are) provided with current leads, in particular in the form of foils or of metal braids.

16. Device according to one of the preceding claims, characterized in that it is an electrochromic system, in particular an “all-solid” or “all-polymer” electrochromic system, with at least one carrier substrate and one stack of functional layers comprising at least successively a first electroconductive layer, an electrochemically active layer capable of reversibly inserting ions such as H ⁺ , Li ⁺ , OH "of the electrochromic material type with anodic or respectively cathodic coloring, a layer d electrolyte, a second electrochemically active layer capable of reversibly inserting ions such as H ⁺ , Li ⁺ , OH "of the electrochromic material type with cathodic or respectively anodic coloring, and a second electroconductive layer, with at least one of the two electroconductive layers in the form of a layer A based on metal oxide (s) and forming part of a multi-component electrode nte E.

17. Device according to one of claims 1 to 15, characterized in that it is a viologen system, with at least one carrier substrate and a stack of functional layers comprising at least, successively, a first electrically conductive layer , a film with viologic properties in the form of a polymer, a gel or a suspension in a liquid medium, a second electroconductive layer, with at least one of the two electroconductive layers of type A based on oxide (s) metallic (s) and forming part of a multi-component electrode E.

18. Device according to one of the preceding claims, characterized in that the stack of functional layers is arranged between two substrates, each of which may be rigid, of the glass or rigid polymer type such as polycarbonate or PMMA, semi- rigid, or flexible of the PET type, and preferably being all transparent, absorbent or not.

19. Glazing characterized in that it incorporates the device according to one of the preceding claims, said device using as carrier substrate at least one of the rigid substrates constituting the glazing and / or at least one flexible substrate associated by lamination with one of the substrates rigid components of said glazing.

20. Use of the device according to one of claims 1 to 18 or of the glazing according to claim 19 for making glazing for buildings, in particular exterior glazing or internal partition or glazed door or roofs, glazing equipping internal partitions or windows or roofs of means of transport such as train, plane, car, boat, viewing screen glazing such as computer or television screen, touch screen, for making glasses or camera lenses photographic or solar panel protections.

21. Use of the device according to one of claims 1 to 18 for making electrochemical energy storage devices of the battery, fuel cell type.