MX2007000873A - Non-oxidised electrolyte electrochemical system - Google Patents

Abstract

The inventive electrochemical system comprises at least one substrate, at least one electroconductive layer, at least one electrochemically active layer for reversibly inserting ions, in particular cations of H+, Li+, Na+, Ag+-type or OH anions and at least one electrolyte functionality layer, wherein the electrolyte comprises at least one substentially mineral layer which is embodied in a non-oxidised form and whose ionic conductivity is generated or amplified by incorporating nitrogenous compound(s), in particular nitrided, optionally hydrogenated or fluorinated.

Description

ELECTROCHEMICAL SYSTEM THAT HAS A NON-OXIDIZED ELECTROLYTE FIELD OF THE INVENTION The present invention relates to the field of electrochemical devices comprising at least one electrochemically active layer capable of reversibly and simultaneously inserting ions and electrons, in particular into the field of electrochemical devices. These electrochemical devices are used especially to manufacture glass assemblies whose transmission of light and / or energy or protection of light and / or energy can be modulated by means of an electric current. They can also be. used to manufacture energy storage elements, such as batteries or gas detectors.

BACKGROUND OF THE INVENTION Taking the particular example of the electrochromic systems, it will be remembered that they comprise, in a known manner, at least one layer of material capable of reversibly and simultaneously inserting cations and electrons, the oxidation states which, corresponding to the inserted and extracted states, they have different colors, one of the states being generally transparent. Many electrochromic systems are built on the following "five-layer" model: TC1 / EC1 / EL / EC2 / TC2, in which TC1 and TC2 are electronically conductive materials EC1 and EC2 are electrochromic materials capable of reversibly and simultaneously inserting cations and electrons, and EL It is an electrolytic material that is an electronic insulator and an ion conductor. The electronic conductors are connected to an external power supply and by applying an adequate potential difference between the two electronic connectors the color of the system can change. Under the effect of the potential difference, the ions are extracted from an electrochromic material and inserted into the other electrochromic material, passing through the electrolytic material. The electrodes are extracted from an electrochromic material and enter the other electrochromic material via electronic conductors and the external energy circuit to counteract the changes and ensure the electrical neutrality of the materials. The electrochromic system is generally deposited on a support, which may or may not be transparent and of organic or mineral nature, which is then called substrate. In certain cases, two substrates can be used, either of the two has part of the electrochromic system and the complete system obtains the two substrates together, or one substrate has the entire system electrochromic and the other is designed to protect the system. When the electrochromic system is intended to work in transmission, the electroconductive materials are generally transparent oxides, the electronic conduction of which has increased by adulteration, such as the In2C > 3: Sn, In203: Sb, ZnO: Al or Sn02: F. Altered or tin-modified aluminum oxide (In203: Sn or ITO) is often chosen for its high electron conductivity and low light absorption properties. When the system is intended to work in reflection, one of the electroconductive materials may be of the metallic type. One of the most used and most studied electrochromic materials is tungsten oxide, which changes from blue to transparent depending on its state of insertion. This is an electrochromic cathodic coloring material, that is to say that its colored state corresponds to the inserted (or reduced) state and its bleached state corresponds to the extracted (or oxidized) state. During the construction of a 5-layer electrochromic system it is common practice to combine this with an electrochromic coloring material, such as nickel oxide or iridium oxide, the coloring mechanism of which is complementary. This results in an improvement in the light contrast of the system.

It has also been proposed to use a material that is optically neutral in the oxidation states in question, such as, for example, cerium oxide. All the materials mentioned above are of inorganic type, but it is also possible to combine organic materials, such as electronically conducting polymers (polyaniline, etc.) or Prussian blue, with inorganic electrochromic materials, or even using only organic electrochromic materials. The cations are usually small monovalent ions, such as H + and Li +, but it is also possible to use Ag + or K + ions. The function of the electrolytic materials is to allow the reversible flow of ions from one electrochromic material to the other, while preventing the flow of electrons. It is generally expected that electrolytes have a high ionic conductivity and behave passively during the flow of ions. Its nature is adapted to the type of ions used for the electrochromic change. The electrolytes can take the form of a polymer or a gel, for example a proton-conducting polymer or a lithium-ion conducting polymer. The electrolyte can also be a mineral layer, especially one based on titanium oxide. The choice of materials is guided by their optical properties but also by considerations of system cost, bioavailability, processability and durability. The terms "durable" and "durability" are used here in the sense of preserving the luminous properties of the systems throughout the period of their use. When all the elements that constitute the electrochromic system are of inorganic nature, they will be referred to as "totally solid" systems, such as those described in patent EP-0 867 752. When some of the materials are of inorganic nature and some of the materials are organic in nature, the systems are referred to as hybrid systems, such as those described in European Patents EP-0 253 713 and EP 0-670 346, for which the electrolyte is a proton-conducting polymer, or those described in the Patents EP-0 382 623, EP-0 518 754 or EP-0 532 408, for which the electrolyte is a conductive polymer of lithium ions. It is possible to insert an additional material between the electrolyte and at least one of the electrochromic materials, to modify the nature of the interface and / or to improve the durability of the system. The aggregate material does not have to completely fill all the usually expected conditions of an electrolyte (for example having a lower electrical resistance or being an electrochromic material), the presence of the initial electrolyte guarantees that the multilayer or multimaterial system thus created will favor the flow of ions, preventing at the same time the flow of electrons. An example is available from patent EP-0 867 752 to which is related to a totally solid electrochromic system in which a layer of tungsten oxide is inserted between the iridium oxide (the electrochromic material) and the tantalum oxide ( the electrolyte). It can be used in the same method in the case of the hybrid system described in the article by K.S. Ahn et al., Appl. Phys. Lett. 81 (2002), 3930. The electrochromic materials are nickel hydroxide and tungsten oxide, and the electrolyte is a solid proton-conducting polymer. An additional tantalide oxide layer has been inserted between each electrochromic material and the electrolytic polymer, since direct contact will degrade the electrochromic materials. By extension, the multilayer or multimaterial system thus created is called electrolyte, since it does not participate in the mechanism of insertion and extraction of ions. These systems are described, for example in the European Patents EP-0 338 876, EP-0 408 427, EP-0 575 207 and EP-0 628 849. Currently, these systems can be placed in two categories, depending on the electrolyte flow they use: • whether the electrolyte is in the form of a polymer or a gel, for example a proton-conducting polymer, such as those described in European Patent EP-0 253 713 and EP-0 670 346, or a conductive polymer of lithium ions, such as those described in the EP-patents 0 382 623, EP-0 518 754 and EP-0 532 408; or the electrolyte is a mineral layer, especially one based on tantalum oxide and / or tungsten oxide, which is an ionic conductor but an electronic insulator, the systems then being referred to as "totally solid" electrochromic systems. The present invention relates more specifically to improvements made to electrolytic systems that fall within the category of fully solid systems, but also intended to be used for hybrid systems or even for systems in which all components are of an organic nature . US 5 552 242 describes an electrochemical system of the totally solid battery type, the electrolyte of which consists a hydrogenated silicon nitride. Furthermore, EP 0 831 360 describes the use of an electrolyte consisting of one or more layers, at least one electrochemically active layer, capable of reversibly inserting ions, especially cations of the type H +, Li +, Na + or Ag +, the which is based on a material essentially mineral, of the oxide type or OH anions. "All these electrophilic devices, the phenomena of insertion / extraction of ions, and therefore the phenomenon of coloration / bleaching in the specific case of the electrochromic systems, is satisfactorily reversible. , in turn, the speed of change from one state to another (coloration / bleaching in the specific case of electroconductive systems) is one of the operating parameters that could be further improved in order to increase the speed of change .

THE INVENTION The object of the present invention is therefore to alleviate this disadvantage by providing an electrolyte for an electrochemical system that improves the rate of change. For this purpose, the objective of the present invention is an electrochemical system comprising at least one substrate, at least one electronically conductive layer, at least one electrochemically active layer capable of reversibly inserting ions, especially cations of the type H +, Li +, Na +, K +, Ag +, or OH anions ", and at least one layer having an electrolyte function, characterized in that the electrolyte is transparent in the visible spectrum and comprises at least one layer made of an essentially mineral material, in non-oxidized form, the ionic conduction of which is generated or improved by the incorporation of one or more nitrogen compounds, in particular optionally hydrogenated or fluorinated nitrides or one or more fluorides. By using an electrolyte, the electrochemical system has a transition speed (rate of change) between a colored / bleached state and vice versa) that is uniquely better over the known electrochemical systems of the prior art. Furthermore, it should be noted that the electrolyte according to the invention can be deposited easily and quickly on a substrate by conventional electrodeposition techniques. In addition, the use of an electrolyte in non-oxidized form offers the advantage of singularly improving the durability of the electrochemical system. Within the context of the invention, the term "electrolyte" mentioned above is a material or a combination of materials that will transfer ions reversibly inserted by the electrochemically active layer or layers of the system. In other preferred embodiments of the invention, one or more of the following arrangements: - the layer that has an electrolyte function is electronically insulating; the layer having an electrolyte function has an absorption in the visible spectrum, for a film of 100 nm, which is better than 20%, preferably less than 10% and more preferably less than 5%; - the layer having an electrolyte function has a thickness between 1 and 500 nm, preferably between 50 and 300 nm and, still more preferably between 100 and 200 nm; the layer having an electrolyte function is based on silicon nitride, boron nitride, aluminum nitride or zirconium nitride, itself or as a mixture, and optionally modified; - the layer having an electrolyte function is a multilayer, which further comprises the layer containing one or more nitrogen compounds, at least one other layer made of an essentially mineral material; - one of the other layers is selected from molybdenum oxide (W03), tantalum oxide (Ta2Os), antimony oxide (Sb205), nickel oxide (NiOx), tin oxide (Sn02), zirconium oxide (Zr02) , aluminum oxide (A1203), silicon oxide (Si02), niobium oxide (Nb20s), chromium oxide (Cr203), cobalt oxide (C0304), titanium oxide (Ti02), zinc oxide (ZnO), optionally alloyed with aluminum and tin oxide and zinc (SnZnOx), vanadium oxide (V205) with at least one of those oxides optionally hydrogenated or nitrated; - the layer having an electrolyte function is a multilayer comprising, in addition to the layer containing one or more nitrogen compounds, at least one other layer made of a polymeric material; - the layer having an electrolyte function is a multilayer comprising, in addition to the layer having one or more nitrogen compounds, at least one other layer based on molten salts; one of the other layers is selected from polymers possessing ionic conduction properties, especially H +, Li +, Ag +, K + and Na +; the other layer of the polymeric type is selected from the polyoxyalkylene family, especially polyoxyethylene, or from the polyoxyethylene family; - the other layer of the polymeric type is in the form of an anhydrous or aqueous liquid or is based on one or more gels, or on one or more polymers, especially an electrolyte of the layer type comprising one or more compounds containing hydrogen and / or contain nitrogen of type POE: H3P04 and also a layer comprising one or more hydrogen-containing and / or nitrogen-containing compounds / PEI: H3PO4 or even more a laminable polymer; and - the electrochemically active layer comprises at least one of the foing compounds: tungsten oxide (W), niobium oxide (Nb), tin oxide (Sn), bismuth oxide (Bi), vanadium oxide (V), nickel oxide (Ni), iridium oxide (Ir), antimony oxide (Sb), and tantalum oxide (Ta), itself or as a mixture, and optionally including an additional metal such as titanium, tantalum or rhenium. The electrochemical device incorporating at least one layer in its electrolyte according to the invention can be designed so that the electrolyte is in fact a multilayer. As a variant, the multilayer incorporating at least one layer of nitride includes other layers of the polymeric type, which are in the form of a polymer or a gene, for example a proton-conducting polymer such as those described in European Patent EP-0 253 713 and EP-0 670 346, or a conductive polymer of lithium ions, such as those described in EP-0 382 623, EP-0 518 754, EP-0 532 408. It can be an interpenetrating network polymer as is described in the application FR-A-2 840 078. In this way, the electrolyte can be a multilayer electrolyte and can contain layers of materials solid or in polymeric form. The monolayer or multilayer electrolyte of the invention has a thickness of more than 5 Dm and is in particular of the order of 1 nm to 1 Dm, in particular for electrochromic glassware applications. Within the context of the invention, it should be understood that the term "solid material" means any material that has the mechanical strength of a solid, in particular any essentially mineral or organic material or any hybrid material, i.e. one that is partially mineral or partially organic, as the materials that can be obtained by sol-gel deposition of organomineral precursors. This therefore results in what is known as "totally solid" system configuration, which has a clear advantage in terms of its manufacturing capacity. This is because, when the system comprises an electrolyte in the form of a polymer that does not have the mechanical strength of a solid for example, this means in effect that it has two "half-cells". which have to be manufactured in parallel, each consisting of a support substrate coated with a first electronically conductive layer and then with a second electrochemically active layer, then those two semicells being mounted with the electrolyte inserted therein. With a "totally solid" configuration, manufacturing it is simplified since it is possible to deposit all the layers of the system, one after the other, on a single support substrate. The device also becomes light, since it is no longer essential to have two support substrates. The invention also relates to all the applications of the electrochemical device that have been described, in particular the foing three applications: the first application relates to electrochromic glassware. In this case, when glassware is intended to operate in variable light transmission mode, it is advantageous for substrates that the device be transparent, whether it is made of glass or plastic. If it is desired to give the glaze a mirror function, and have it operate in the variable light reflection mode, several solutions are possible: any of the substrates that are chosen as opaque and reflector (for example a metal plate, or the device is combined with an opaque and reflective element, or one of the electrically conductive layers of the devices is chosen so that it is mechanical in nature and thick enough to be reflective, especially when glassware is intended to operate in the transmission mode of variable light with a device provided with one or two transparent substrates, a multiple glazing unit can be mounted, especially as a double glass unit, with another transparent substrate and / or a laminated glassware unit: the second application relates to elements that store energy, more particularly with batteries that incorporate especially hydrides, which can be used for example in any equipment that implies electronic and / or computer means, and any equipment that requires any storage device that is intrinsic to it, whether autonomous or not, or also as material for the production of dark windows, when this nitrated electrolyte is associated with materials whose change is accompanied by the formation or by the decomposition of a hydride of Ti, V, Cr, Mn, Fe, Gd, Ni, Cu, Zn, Zr, Nb, Mo, Te, Ru, Rh, Pd, Ag , Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg or Mg, itself or as a mixture, optionally alloyed with Gd; and the third application is related to gas detectors. These gas detectors are related in a particular way in an industrial or commercial or domestic environment, as means to control or verify physical, chemical or physicochemical measuring instruments. Returning to the first application, that of electrochromic glasses, these can be used advantageously as windows for buildings or for automobiles, windows for commercial vehicles / mass transit, windows for land, air, river or maritime transport, as mirrors and as other driving mirrors, or as optical elements, as camera lenses, or also, face or front element to be placed in or near the front face of display screens for equipment such as computers or televisions. It has been proven that it is preferable, especially in the application of electrochromic glasses, to have a laminated structure of the type: transparent substrate (glass, PC, PMMA, PET, etc.) / functional multilayer / polymer interlayer / transparent substrate (glass, PC, PMMA, PET, etc.). If the substrates are made of glass, they can be made of a clear or dark glass, they can be flat or curved and can be reinforced by a chemical or thermal reinforcement, or simply hardened. That thickness can vary between 1 mm and 19 mm, depending on the expectations and requirements of the end users. The substrates can be partially coated with an opaque material, in particular around its periphery, particularly for aesthetic reasons. The substrates can also possess an intrinsic functionality (coming from a multilayer consisting of a single layer of solar control, antireflection, low emissivity, hydrophobic, hydrophilic or otherwise) and in this case the assembly of electrochromic glasses combines the functions provided by each element to satisfy the requirements of the users. The polymeric insert is used here for the purpose of joining the two substrates together by the lamination process widely used in the automotive and construction fields, to provide a safe and comfortable product: bulletproof or anti-ejection safety, to be used in the field of transport, and anti-theft security (unbreakable glass) to be used in the field of construction or, thanks to this lamination insert, provide acoustic functionality, sun protection or coloration. The rolling operation is also favorable in that sense that it isolates the functional multilayer from chemical or mechanical attack. The interlayer is preferably chosen so that it is based on ethylene / vinyl acetate (EVA) or its copolymers, it can also be made of polyurethane (PU), polyvinyl butyral (PVB), or a one component or multiple component resin that can be cured with heat (epoxy or PU) or cured with UV (epoxy or acrylic resin). The lamination insert is generally transparent, but can be completely or partially colored to satisfy the wishes of the users.

The insulation of the multilayer from the outside, it is usually effected by seal systems placed along the extreme faces of the substrates, or actually partially within the substrates. The lamination insert may also include additional functions, such as a sun protection function provided for example by a plastic film comprising multilayers of ITO / metal / ITO or a film composed of an organic multilayer. The devices of the invention when used as batteries can also be used for the fields of construction or vehicles, or they can be part of the equipment of a type of computer, television or telephone. The invention also relates to a process for manufacturing the device according to the invention, in which the electrolyte layer of the invention forming part of the electrolyte can be deposited by a vacuum technique, of the cathodic electrodeposition type, possibly electrodeposition magnetically improved, by thermal evaporation or evaporation with electron beam, laser ablation, by CVD (Chemical Vapor Deposition), optionally plasma enhanced or improved with microwave. The electrolyte layer of the invention that forms part of the electrolyte can be deposited by an atmospheric pressure technique, in particular by the deposition of layers by sol-gel synthesis, especially dip coating, spray coating or coating. flow, or by CVD with plasma at atmospheric pressure. It is also possible to use a powder or liquid phase pyrolysis technique or a gas phase pyrolysis technique such as CVD, but at atmospheric pressure. Indeed, it is particularly advantageous here, to use a vacuum deposition technique, especially of the electrodeposition type, since the characteristics of the layer constituting the electrolyte (deposition rate, density, structure, etc.) can therefore both be controlled in a very fine way. In this way, it is possible to deposit the electrolyte layer by reactive cathodic electrodeposition in a sample containing nitrogen compounds or their precursors. Within the context of the invention, it should be understood that the term "precursors" means molecules or compounds that are capable of interacting and / or decomposing under certain conditions to form the desired nitrogen compound in the layer. In order to deposit an electrolyte layer according to the invention that is nitrated, a gaseous precursor, especially one based on NH 3 or more generally a nitrogen-based precursor, especially in the form of an amine, imine, hydrazine or N2, in the electrodeposition chamber. The electrolyte layer according to the invention can also be deposited by thermal evaporation as mentioned above. It can be evaporation with electron beam, the hydrogen and / or nitrogen compounds or their precursors being introduced into the layer in gaseous form and / or being contained in the materials that are intended to be evaporated. The electrolyte layer according to the invention can also be deposited by a sol-gel technique. The content of hydrogen and / or nitrogen compounds is controlled by several means: it is possible to adapt the composition of the solution, so as to contain those compounds or their precursors, or the composition of the atmosphere in which the deposition takes place. It is also possible to refine this control by adjusting the deposition / curing temperature of the layer.

BRIEF DESCRIPTION OF THE FIGURES Other features and advantageous details of the invention will emerge from the description given below with reference to the accompanying drawings which represent: Figure 1 is a front view of the face 2 according to the invention; Figure 2 is a sectional view on AA of Figure 1; Figure 3 is a sectional view on BB of Figure 1; Figure 4 is a graph illustrating the rate of change of an electrochemical system according to the prior art compared to that of an electrochemical system incorporating an electrolyte according to the invention; and Figure 5 shows a graph illustrating the influence of an electrolyte according to the invention on the rate of change.

DETAILED DESCRIPTION OF THE INVENTION In the annexed drawings, certain elements have been shown on a smaller or larger scale than in reality, to facilitate the understanding of the figures. The example illustrated in Figures 1, 2 and 3 is related to an electrochromic glass unit 1. This comprises, in succession from outside the passenger compartment inwards, two crystals SI, S2, which are made of silicate glass, soda -cal clear (but possibly also dyed) for example with 2.1 mm and 2.1 mm, respectively. The crystals Si and S2 are the same size, with dimensions of 150 mm x 150 mm. The crystal SI shown in FIGS. 2 and 3 has, on the face 2, a thin film multilayer of the totally solid electrochromic type. The SI glass was laminated to the S2 crystal via a thermoplastic sheet fl of 0.8 mm thick polyurethane (PU) (this can be replaced by an ethylene / vinyl acetate (EVA) or polyvinyl butyral (PVB) sheet). The "totally solid" electrochromic thin film multilayer comprises an active multilayer 3 placed between two electronically conductive materials, also referred to as current collectors 2 and 4. The collector 2 is intended to be in contact with the face 2. The collectors 2 and 4 and the active multilayer 3 may be substantially the same size and shape, or substantially of different size and shape, and it should be understood therefore that the trajectory of collectors 2 and 4 will be designed according to the configuration. In addition, the dimensions of the substrates, in particular SI, can be substantially greater than those of those of 2, 4 and 3.

The collectors 2 and 4 are of the metallic type or of the TCO (Transparent Conductive Oxide) type made of ITO, Sn02: F or ZnO: Al, or can be a multilayer of the TCO / metal / TCO type, this metal being selected in particular from silver, gold, platinum and copper. It can also be a multilayer of NiCr / metal / NiCr type, with the selected metal being in particular silver, gold, platinum and copper. Depending on the configuration, it can be omitted, and in this case the current cables are directly in contact with the active multilayer 3. The glass unit 1 incorporates power cables 8, 9 which control the active system via a power supply. These power cables are of the type used for hot windows (ie, supplemented by a thin layer, wires or the like). A first preferred embodiment of the collector 2 is one formed by depositing on the face 2, a first layer of SiOC 50 nm thick followed by a second layer of Sn02: F 400 nm thick (preferably two layers deposited in succession by CVD on floating glass before cutting). A second embodiment of the collector 2 is one formed by depositing, on the face 2, a modified bilayer (specially modified with aluminum or modified with boron) or unmodified consisting of a first layer based on Si02 of approximately 20 nm in thickness followed by a second ITO layer of approximately 100 to 600 nm in thickness (two layers being preferably deposited in succession, under vacuum, by reactive magnetron electrodeposition in the presence of oxygen and optionally carried out in hot) . Another embodiment of the collector 2 is one formed by depositing, on layer 2, a monolayer consisting of ITO of approximately 100 to 600 nm thickness (a layer preferably deposited under vacuum, by reactive magnetron electrodeposition in the presence of oxygen and optionally carried out in hot) . The collector 4 is an ITO layer of 100 to 500 nm, also deposited by reactive magnetron electrodeposition on the active multilayer. The active multilayer 3 shown in FIGS. 2 and 3 is constituted as follows: a layer of 100 to 300 nm of anodic electrochromic material made of nickel oxide, possibly alloyed with other metals. As a variant (not shown in the figures), the layer of anodic material is based on a layer of 40 to 100 nm of iridium oxide; • a 100 nm layer of tungsten oxide; • a 100 nm layer of hydrated tantalum oxide or hydrated silicon oxide or hydrated zirconium oxide, or a mixture of those oxides; and • a layer of cathodic electrochromic material based on tungsten oxide hydrate with a thickness of 200 to 500 nm, preferably 300 to 400 nm, for example about 370 nm. The active multilayer 3 can be cut on all or part of its periphery with grooves produced by mechanical means or by laser engraving, possibly using a driven laser. This is done to limit peripheral electrical leakage, as described in French application FR-2 781 084. The glass unit shown in figures 1, 2 and 3 is also incorporated (but not shown in the figures) a first peripheral seal in contact with faces 2 and 3, this first seal being designed to form a barrier against external chemical attack. A second peripheral seal is in contact with the edge of the SI, the edge of S2 and the face 4 to form a barrier and means for mounting the glass on the vehicle, to provide a seal between the inside and the outside, and to form a attractive feature, and to form means for the incorporation of reinforcement elements.

Figure 4 (see curve 1) shows the variation in the transmission of light measured at the center of the glass when it is subjected to a coloring / bleaching cycle by means of a voltage impulse. If this active multilayer is provided with a voltage impulse, the glass is found, with an electrolyte according to the prior art, it takes approximately 80 s to change from the colored state to the whitened state (the reader can refer to figure 4). On the basis of this same active multilayer, if at least one of the oxide-based layers constituting the electrolyte is replaced with a layer according to the teachings of the invention, that is to say a layer with a thickness between 10 nm and 300 nm, made of silicon nitride, boron nitride, aluminum nitride or zirconium nitride, itself or as a mixture, and optionally modified, then it is found that the glass changes from a colored state to a bleached state in less than 15 s, for the same voltage impulse, all other things being equal. It should also be noted that the coloring speed is higher (see the slope at the origin, which is very steep in curve 2). Figure 5 shows the variation in the transmission of light measured at the center of the glass as a function of time, this glass comprising a active multilayer structure according to the above described, for which the electrolyte layer is a monolayer according to the teachings of the invention (curve 1) or a bilayer based on a mineral oxide and on an electrolyte layer according to the teachings of the invention (curve 2). The predominant influence of the nitride layer on the rate of change between the colored state and the bleached state of the active system, whether or not the layer according to the invention is associated with a layer based on a mineral oxide, can be noted by therefore. According to yet another embodiment of the invention, the electrolyte layer is inserted according to the teachings of the invention between two electrolyte layers based on mineral oxide. In this way, it is possible to have for example TA205 / the layer according to the invention / Ta2Os. According to other variations, the "fully solid" active multilayer 3 can be replaced with other families of polymeric type electrochromic materials. Thus, for example, a first part formed of a layer of electrochromic material, under other circumstances called the active layer, made of poly (3,4-ethylenedioxythiophene) of 10 to 10000 nm, preferably 50 to 500 nm, of thicknesses - with one variant, it can be one of the derivatives of this polymer - is deposited by known liquid deposition techniques (spray coating, dip coating, spin coating, or flow coating) or also by electrodeposition, on a substrate coated with its current collector, possibly causing This current collector has a lower or upper conductive layer that forms the electrode (anode or cathode) optionally provided with wires or the like. Whichever polymer constitutes this active layer, this polymer is particularly stable, especially under UV, and operates by insertion / extraction of lithium ions (Li +) or, alternatively, of H + ions. A second part that acts as an electrolyte, and formed of a layer with a thickness of between 50 nm and 2000 and, preferably, between 50 nm and 1000 nm, is deposited by a known liquid deposition technique (spray coating, dip coating, spin coating, or flow coating) between the first and third parts on the first part, or also by injection. This second part is based on a polyoxyalkylene, especially polyoxyethylene. As a variant, it can be a mineral-type electrolyte based, for example, on hydrated tantalum oxide, zirconium oxide or silicon oxide.

This second part of the electrolyte deposited on the layer of the active electrochromic material, which is itself supported by the glass or a similar substrate, is then coated with a third part, the constitution of which is similar to that of the first part, that is, this third part. It is constituted by a substrate, covered with a current collector (conductive wires, conductive wires + conductive layer, a conductive layer only), this current collector itself being covered with an active layer. On the basis of this fully polymeric multi-layer electrochromic, it is proposed to replace one of the layers forming the electrolyte with at least one layer having a similar function but according to the teachings of the invention. A layer according to the teachings of the invention is inserted between one of the active layers and one of the layers that form the electrolyte or in the middle part of the layers that form the electrolyte. According to another embodiment, it is proposed to replace one of the oxide layers that form the electrolyte in a hybrid multilayer (solid / polymer) with a non-oxidized layer according to the invention and insert a non-oxidized layer according to the invention between the material or the inorganic active materials and the polymer that acts as an electrolyte as in the previous example, this insertion can be according to one of the following configurations: a layer according to the teachings of the invention between one of the active layers and one of the layers forming the electrolyte or the middle part of the layers forming the electrolyte This example corresponds to a glass that operates by proton transfer. It consists of a first glass substrate 1, made of a 4 mm thick soda-lime silicate glass, followed in succession by: • a first electron-conductive Sn02: F layer of 300 nm; • a first anodic layer of 185 nm of electrochromic material consisting of nickel oxide hydrated NiO > Hy (this can be replaced by a 55 nm layer of hydrated iridium oxide). • an electrolyte consisting of a first layer of 70 nm of hydrated tantalum oxide, according to the 100 micrometer layer of a solid solution of polyoxyethylene / phosphoric acid POE / H3PO4, or alternatively a solid solution of polyethylenimine / phosphoric acid PEI / H3P04; • a second layer of 350 nm of cathodic electrochromic material based on tungsten oxide; Y • a second layer of Sn02: F of 300 nm followed by a second glass substrate identical to the first one. For example, there is therefore a bilayer electrolyte based on a polymer normally used in this type of glass, which is "coated" with one. tantalum hydroxide layer which is sufficiently conductive not to impart proton transfer via the polymer that protects the counter electrode made of anodic electrochromic material in direct contact with the latter, the intrinsic acidity of which would be detrimental to it. Instead of the hydrated Ta205 layer, a layer of Sb2Os or of the hydrated TaWOx type is used. It is also possible to provide an electrolyte with three layers, with two layers of hydrous oxide, either with one of them on each side of the polymer layer, or with the two layers superposed one on the other on the side facing the layer of anodic electrochromic material. On the basis of this example, at least one of the layers having an electrolyte function based on tantalum oxide, antimony oxide or tungsten oxide replaced with at least one non-oxidized electrolyte layer according to the invention. A non-oxidized electrolyte layer according to the invention can also be inserted between the electrochromic material layer cathode and the solid solution of PCE / H3P04 or PEI / H3P04. According to another variant, the layer according to the invention is inserted in a solid solution of According to another embodiment of the invention, the electrolyte is combined with a multilayer based on hydride materials capable of changing in transmission to light or reflection to light, for which the change is accompanied by the formation or the decomposition of hydrides. This is formed in a manner similar to the fully solid glass described above, ie the compound of an active multilayer 3 placed between two current collectors 2 and 4 and operates by insertion / extractions of H + ions. The active multilayer 3 is constituted as follows: a layer of 20 to 100 nm made of a transition metal and in particular magnesium, which can be alloyed another transition metal, and in particular nickel, cobalt or manganese; a layer according to the invention, ie the layer with a thickness between 10 nm and 300 nm of silicon nitride, boron nitride, aluminum nitride or zirconium nitride, itself or as a mixture and optionally modified; optionally, a palladium layer with a thickness between 1 nm and 10 nm is inserted between the magnesium-based layer and the layer according to the invention; a 100 nm layer consisting of a layer made of hydrated tantalum oxide or hydrated silicon oxide or zirconium oxide hydrate or a mixture of these oxides; and a 370 nm layer of cathodic electrochromic material based on tungsten hydrated oxide. As a variant, a layer according to the invention is placed on either side of a palladium layer. The active multilayer thus formed changes in deflection and in transmission, the change in appearance in reflection not being the same according to whether the observer sees it from the side of the hydride layer or the side of the tungsten oxide layer. When the potential difference at which the two electronically conducting layers 2 and 4 are subjected by the external power supply system (not shown) is such that the protons are predominantly in the tungsten oxide layer, the layer is colored and the magnesium-based layer is in the metallic and reflective state. The light transmission of the glass is smaller than 1% due to the metallic state of the magnesium-based layer, which reflects most of the light. Seen in reflection on the magnesium-based layer, the glass is reflective and slightly colored, with a light reflection of between 40% and 80% depending on the thickness of the magnesium-based layer. When viewed in reflection on the side of the tungsten oxide layer, the glass seems colored with a light reflection of between 5% and 20%, depending on the color and light reflection level of both the thickness of the layer constituting the multilayer and the applied potential difference. When the potential difference at which the two electronically conductive layers 2 and 4, which are associated with the current collectors via the external energy supply system (not shown), are subjected is such that the protons are predominantly in the magnesium based layer, the latter is in a semiconducting and bleached state and the tungsten oxide layer is in a bleached state. The light transmission of the glass is maximum, being between 20% and 50% depending on the thickness of the magnesium-based layer and in the presence of the palladium layer. The reflection of light measured on the other magnesium-based layer is between 10% and 30%, as is the reflection of light measured on the side of the tungsten oxide layer.

The changes in the reflection and transmission properties within the visible wavelength range (380 nm - 780 nm) mentioned in the previous example are also valid in the infrared range (> 780 nm), ie the reflection and transmission of glass energy varies in the same way as reflection and transmission of light. Certain systems also have the characteristic of passing through intermediate absorbing states, in which both the light reflection and the light transmission of the magnesium-based layer pass through a minimum. Optionally, the magnesium-based hydride layer described above can be replaced by a rare earth-based hydride layer (Gd, La, Y, etc.) optionally alloyed with a transition metal such as magnesium. One of the current collectors 2 and 4 mentioned in the example can be omitted, in particular one in contact with the hydride layer if its electronic conductivity is sufficiently high. According to another application of the layer according to the invention, it is used in fuel cells as a means to transport ions, especially H + or O2".

Claims (22)

1. CLAIMS 1. Electrochemical system comprising at least one substrate, at least one electronically conductive layer, at least one electrochemically active layer capable of reversibly inserting ions, especially cations of the type H +, Li +, Na +, K +, Ag + or OH anions " , and at least one layer having an electrolyte function, characterized in that the electrolyte is transparent in the visible spectrum and comprises at least one layer consisting of an essentially mineral material, in non-oxidized form, the ionic conduction from which it is generated or improved by the incorporation of one or more nitrogen compounds, in particular optionally hydrogenated or fluorinated nitride 2. Electrochemical system according to claim 1, characterized in that the layer having an electrolyte function is electronically insulating 3. Electrochemical system according to any of the claims 1 or 2, characterized in that the absorption in the visible spectrum of the layer that it has an electrolyte function, for a film of 100 nm, it is less than 20%, preferably less than 10% and even more preferably less than 5%. 4. Electrochemical system according to any of claims 1 and 2, characterized in that the layer having an electrolyte function has a thickness of between 1 and 500 nm, preferably between 50 and 300 nm and more preferably between 100 and 200 nm. Electrochemical system according to any of the preceding claims, characterized in that the layer having the electrolyte function is based on silicon nitride, boron nitride, aluminum nitride or zirconium nitride, itself or as a mixture, and optionally modi ficado Electrochemical system according to any of the preceding claims, characterized in that the layer having the electrolyte function is a multilayer comprising, in addition to the layer containing one or more nitrogen compounds, at least one other layer consisting of an essentially mineral material . Electrochemical system according to claim 6, characterized in that the other layers are selected from molybdenum oxide (W03), tantalum oxide (Ta2C> 5), antimony oxide (Sb2C> 5), nickel oxide (NiOx) , tin oxide (Sn02), zirconium oxide (Zr02), aluminum oxide (A1203), silicon oxide (S1O2), niobium oxide (Nb205), chromium oxide (Cr203), cobalt oxide (CO3O4), titanium oxide (Ti02), zinc oxide (ZnO), vanadium oxide (V2O5) optionally alloyed with aluminum and tin oxide and zinc (SnZnOx), at least one of these oxides being optionally hydrogenated or nitrated. 8. Electrochemical system according to any of claims 1 to 5, characterized in that the layer having an electrolyte function is a multilayer comprising, in addition to the layer containing one or more nitrogen compounds, at least one other layer consisting of a polymeric material or one based on molten salts. Electrochemical system according to claim 8, characterized in that one of the other layers is selected from polymers possessing ionic conduction properties, especially H +, Li +, Ag +, K + and Na +. 10. Electrochemical system according to claim 8 or claim 9, characterized in that the other layer of polymeric type is selected from the polyoxyalkylene family, especially polyoxyethylene, or from the family of polyethylene imines. Electrochemical system according to claim 8 or claim 9, characterized in that the other polymer-type layer is in the form of an anhydrous or aqueous liquid or is based on one or more gels, or one or more polymers, especially an electrolyte of the type of layer comprising one or more compounds containing hydrogen and / or containing nitrogen of the POE: H3P04 type and also a layer comprising one or more nitrogen containing and / or containing compounds / PEI: H3PO4 or even more a laminable polymer . 12. Electrochemical system according to claim 1, characterized in that the electrochemically active layer comprises at least one of the following compounds: tungsten oxide (W), niobium oxide (Nb), tin oxide (Sn), bismuth oxide (Bi), vanadium oxide (V) , nickel oxide (Ni), iridium oxide (Ir), antimony oxide (Sb), and tantalum oxide (Ta), itself or as a mixture, and optionally including an additional metal such as titanium or rhenium. Electrochromic glass, characterized in that it comprises the electrochemical system according to one of the preceding claims, which has in particular a transmission and / or reflection of light and / or variable energy, with the substrate or at least part of the transparent or partially transparent substrate made of glass or made of plastic, preferably mounted as a multiple and / or laminated glass, or as a double glazing. Electrochromic glass, comprising the electrochemical system according to one of claims 1 to 12, characterized in that it is combined with at least one layer suitable for providing the glass with additional functionality (solar control, low emissivity, hydrophobic, hydrophilic, antireflection). 15. Electrochromic glass, which incorporates a layer that has an electrolyte function according to one of the claims, 1 to 12, characterized in that the layer is associated with materials whose change is accompanied by the formation or decomposition of a Ti hydride, V, Cr, Mn, Fe, Gd, Ni, Cu, Zn, Zr, Nb, Mo, Te, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Go, Pt, Au, Hg og, in itself or as a mixture, optionally alloyed with Gd. 16. Gas detector, characterized in that it comprises an electrochemical system according to one of claims 1 to 12. 17. Process for manufacturing the electrochemical device according to one of claims 1 to 12, characterized in that the layer has an electrolyte function deposited by a vacuum technique, of the cathodic electrodeposition type, possibly magnetically improved electrodeposition, by thermal evaporation or by evaporation with electron beam, by laser abrasion, by CVD, optionally improved with plasma or improved by microwaves, or by a technique at atmospheric pressure , especially by the deposition of the layer by sol-gel synthesis, especially of the coating type by immersion, spray coating or flow coating, or by CVD or plasma at atmospheric pressure, or also by a powder pyrolysis technique or by liquid phase or a gas phase pyrolysis technique of the CVD type at atmospheric pressure delicious. 18. Process according to claim 17, characterized in that the layer having an electrolyte function containing nitrogen compounds is deposited by reactive electrodeposition in an atmosphere containing nitrogen compounds, or precursors of the compounds, especially in the form of gaseous precursors, in particular those based on NH3 or N2, or more generally a nitrogen-based precursor. Process for manufacturing an electrochemical system according to one of claims 1 to 12, characterized in that at least one of the electrochemically active layers is deposited using a vacuum technique, especially by reactive electrodeposition or reactive magnetron electrodeposition, in the DC, DC mode. driven, AC or RF. 20. Use of the glass according to one of claims 12 to 14, in windows for building, windows for automobiles, windows for commercial or railway vehicles, maritime or mass air transport, or as driving mirrors or other mirrors. 21. Use of the energy storage element according to claim 15 in equipment that involves electronic and / or computing means and in equipment that requires an energy storage device that is intrinsic to it, whether autonomous or not, particularly computers, televisions or telephones. 22. Use of the gas detector according to claim 16, especially within an industrial or commercial or domestic environment, as means of control or verification for physical, chemical, physicochemical measuring instruments.