Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect
  • G02F1/1514—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect
  • G02F1/1514—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material
  • G02F1/1523—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material comprising inorganic material
  • G02F1/1524—Transition metal compounds
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect
  • G02F1/153—Constructional details
  • G02F1/155—Electrodes

Definitions

• the present invention relates to the field of electrochemical devices with electrically controllable optical and / or energy properties, commonly known as “electrochromic devices”. More particularly, the invention relates to optical systems integrating such electrochemical devices as well as to the associated manufacturing processes.
• Electrochromic devices exhibit certain characteristics which can be modified under the effect of an appropriate power supply, between a clear state and a tinted state, most particularly the transmission, absorption, reflection in certain wavelengths of the electromagnetic radiation, in particular in the visible and / or in the infrared, or even light diffusion.
• the variation in transmission generally occurs in the optical field (infrared, visible, ultraviolet) and / or in other fields of electromagnetic radiation, hence the name of device with variable optical and / or energy properties, the optical field n ' not necessarily being the only area concerned.
• the glazing From a thermal point of view, the glazing, the absorption of which can be modified in at least part of the solar spectrum, makes it possible to control the solar gain inside the rooms or passenger compartments / compartments when they are mounted in external glazing of building or windows of means of transport of the car, train, plane type, and to prevent them from overheating in the event of strong sunlight.
• an electrochromic stack comprises two electrodes interposed between two transparent electrically conductive layers.
• At least one of these electrodes consists of an electrochromic material which, by definition, is suitable for reversibly and simultaneously inserting ions and electrons, the oxidation states corresponding to the inserted and removed states being of distinct coloration, one of the states exhibiting a higher light transmission than the other.
• the insertion or deinsertion reaction is controlled by means of two transparent conductive layers, the power supply of which is provided by a current generator or a voltage generator.
• a first electrode called a working electrode
• a working electrode is made of a cathodic electrochromic material suitable for picking up ions when a voltage is applied across the electrochromic system.
• the tinted state of the working electrode corresponds to its most reduced state.
• this working electrode is a second electrode, called a counter electrode, which is also capable of reversibly inserting cations, symmetrically with respect to the working electrode.
• this counter electrode is thus adapted to give up ions when a voltage is applied to the terminals of the electrochromic system.
• This counter-electrode consists of a neutral layer in coloring, or at least not very colored when the working electrode is in the clear state, and preferably has a coloring in the oxidized state so as to increase the contrast. total of the electrochromic stack, between its tinted state and its clear state.
• the working electrode and the counter-electrode are separated by an interfacial region commonly called "electrolyte" (in English: long-conductor (IC)) having a dual function of ionic conductor and electrical insulator.
• IC long-conductor
• the ionically conductive layer therefore prevents any short circuit between the working electrode and the counter electrode. It also allows the two electrodes to retain a charge and thus maintain their clear and tinted states.
• such an electrolyte is formed by depositing between the working electrode and the counter-electrode of a separate intermediate layer.
• the boundaries between these three layers are defined by changes sudden changes in composition and / or microstructure.
• Such electrochromic stacks therefore have at least three distinct layers separated by two distinct abrupt interfaces.
• the working electrodes and the counter-electrodes are placed one above the other and generally in contact with one another, and a transition region having the function of electrolyte is formed only subsequently, by migration of components within the electrodes during the manufacturing process and in particular during the heating phases of the stack.
• thermal toughening process nevertheless has the major drawback of forcing the glassmaker to cut the glass to the desired geometry before the toughening step. Indeed, once tempered, the glass can no longer be cut, or it will suffer catastrophic breakage into small pieces, due to internal stresses generated during quenching. Thermal quenching has the additional drawback of destroying the functionalities of known electrochromic stacks, thus rendering the associated devices inoperative.
• the first alternative is to first cut the glass to the desired dimensions, then to temper it, and finally to coat it with the electrochromic stack.
• the production of electrochromic devices must therefore be carried out "tailor-made” from the very first stages of depositing the electrochromic stack. This lack of dimensional standardization of the coated substrates significantly complicates the general process for manufacturing electrochromic glazing, and in particular reduces its productivity.
• the second alternative is to deposit the electrochromic stack on a non-hardened substrate, then to laminate the latter with a counter-substrate, the substrate and the counter-substrate being separated from each other by a spacer made up of for example poly (vinyl butyral) (PVB).
• PVB poly (vinyl butyral)
• the technique proposed in at least one particular embodiment, relates to a cathode sub-assembly for an electrochromic system, said cathode sub-assembly being adapted to be deposited above a substrate with glass function, and comprising at least:
• a working electrode arranged above said first transparent conductive layer, said cathode sub-assembly being characterized in that said working electrode is adapted by virtue of its chemical composition to be functional after thermal quenching.
• the expression "by virtue of its chemical composition” relates exclusively to the proportion of pure substances initially and intrinsically composing each of the electrodes. This concept therefore excludes the mobile ions which can subsequently be introduced into the stack in order to cause its coloring / discoloration as a function of the voltage applied to the terminals of the stack.
• an electrode is said to be “functional” when it has a capacity greater than or equal to 5 mC / cm 2 , regardless of its thickness.
• such an electrode exhibits “optimal” operation when its capacity is greater than 15 mC / cm 2 , preferably greater than 20, 25, 30, 40, 50, 60, 70 mC / cm 2 .
• the measurement of the capacitance of such an electrode can be carried out via any known method, and in particular via a three-electrode test such as that described in the remainder of the text.
• An electrochromic system is said to be “functional” when it exhibits a contrast, between the light state and the dark state, greater than 2.
• a contrast between the light state and the dark state, greater than 2.
• an electrochromic system exhibits "optimal” operation when its contrast. is greater than 5, preferably greater than 20, preferably greater than 100, 200, 300, 400, 500, 650, 800, 1000.
• the contrast measurement can be carried out by any known method, and in particular by means of two coupled electrodes with a Luminous Transmission (TL) measuring device, as described in the rest of the text.
• TL Luminous Transmission
• a cathode sub-assembly according to the invention has the advantage of being resistant to quenching or in other words, to be functional, or preferably to have optimal operation after such a thermal quenching step, and this because of its chemical composition.
• Such a cathode sub-assembly can therefore be produced on a substrate of standard size, to be subsequently cut and tempered with regard to a specific application envisaged.
• the working electrode is deposited by magnetron.
• the deposition is carried out by liquid.
• said working electrode is at least composed of a tungsten oxide (WOx) doped with at least one transition metallic element Y chosen from the group comprising Niobium (Nb), Molybdenum (Mo), Vanadium (Va), Tantalum (Ta), Titanium (Ti), Nickel (Ni), Zinc (Zn) ), Zirconium (Zr).
• WOx tungsten oxide
• transition metallic element Y chosen from the group comprising Niobium (Nb), Molybdenum (Mo), Vanadium (Va), Tantalum (Ta), Titanium (Ti), Nickel (Ni), Zinc (Zn) ), Zirconium (Zr).
• Such a cathode sub-assembly has a further improved resistance to thermal quenching.
• tungsten oxide WOx
• metallic element Y makes it possible to limit the crystallization of tungsten oxide during quenching.
• This electrode then retains a satisfactory capacity to be functional, especially as the molar proportion of doping element approaches the preferred ranges mentioned above.
• said at least one metallic transition element Y is present in a Y / (Y + W) ratio greater than or equal to 2 atomic%, preferably greater than or equal to 5 atomic%, preferably greater or equal to 7 atomic%, preferably greater than or equal to 8 atomic%, preferably greater than or equal to 9 atomic%, and / or less than or equal to 30 atomic%, preferably less than or equal to 20 atomic%, preferably less than or equal to 15 atomic%, preferably less than or equal to 13 atomic%, preferably less than or equal to 11 atomic%.
• the invention also relates to a method of manufacturing such a cathode sub-assembly on a substrate with a glass function, said method preferably implementing at least one deposition station equipped with one or more targets suitable for deposition. by magnetron of said working electrode (3) above the first transparent conductive layer (2A).
• the working electrode is deposited by magnetron at a temperature below 180 ° C, preferably below 160 ° C, preferably below 140 ° C.
• the deposition by magnetron at a temperature below 180 ° C, said cold, has the advantage of not requiring the implementation of an additional heating device in the deposition zone.
• the edges of said substrate are ground before and / or after the deposition of said working electrode.
• the invention also relates to an electrochromic system suitable for being deposited above a substrate having a glass function, and comprising:
• the invention also relates to an electrochromic system suitable for being deposited above a substrate having a glass function, and comprising:
• Lithium (Li) ions introduced into said electrochromic system, - And preferably a separate layer of an ionic conductor interposed between the electrode and the counter-electrode.
• the step of introducing Lithium (Li) ions into said electrochromic system can be carried out in different ways.
• one or more distinct lithium layers are interposed within the electrochromic system.
• the lithium ions are subsequently caused to diffuse within the electrochromic stack, spontaneously and / or under the effect of a rise in temperature.
• said counter-electrode is at least composed of a tungsten-nickel oxide (NiWxOz), preferably doped with at least one metal transition element.
• the thickness of the working electrode (3) is between 100 and 1500 nm, preferably between 150 and 1000 nm, preferably between 200 and 700 nm, preferably between 300 and 500 nm, preferably between 350 and 450 nm, and /or
• the thickness of the counter-electrode (5) is between 100 and 1500 nm, preferably between 150 and 500 nm, preferably between 200 and 350 nm, preferably between 225 and 300 nm, preferably between 260 and 280 nm.
• the invention also relates to a method of manufacturing such an electrochromic system on a substrate with a glass function.
• the invention also relates to the thermal quenching of such a cathode sub-assembly, arranged above a substrate with a glass function, and preferably integrated in such an electrochromic system.
• the thermal quenching step is implemented on the the entire electrochromic stack, and therefore also on the electrochromic subassembly which composes it.
• said thermal quenching is carried out on a cathode sub-assembly and a substrate which has not been previously annealed.
• an annealing step refers to a heating cycle of a material comprising a gradual rise in temperature, to a temperature below 600 ° C, followed by gradual and controlled cooling. This action is particularly used to facilitate the relaxation of stresses that can accumulate in the heart of matter.
• Such an annealing step is therefore distinguished from quenching by its processing temperature ranges, lower than those of thermal quenching, and above all by the gradual nature of the subsequent cooling. Annealing thus aims at an effect opposite to that of quenching, the latter having the objective of generating internal stresses within the material, while annealing aims on the contrary to relax the material, by releasing these internal stresses.
• the invention further relates to a quenched electrochromic system obtained after such thermal quenching.
• the working electrode of such a subassembly has the advantage of being functional after thermal quenching.
• the functional electrodes after quenching are distinguished from known electrodes, non-functional after quenching, by the absence or almost absence of crystallized U2W207 and / or U2W04, which significantly impair its operation, and by the presence of U2W5016.
• the invention also covers obtaining an electrochromic device by assembling a hardened cathode sub-assembly on the one hand, and an anode sub-assembly on the other hand.
• Such an anode sub-assembly comprises at least one counter-substrate above which are deposited a second transparent conductive layer and a counter-electrode.
• said anode sub-assembly is thermally hardened.
• the invention further relates to a glazing incorporating such a tempered electrochromic system, said glazing being suitable for use as building glazing, in particular external glazing of an internal partition or of a glazed door, or as glazing fitted to the partitions.
• internal or windows of means of transport such as train, plane, car, boat.
• Figure 1 is a schematic representation of an electrochromic system according to a particular embodiment of the invention.
• Figure 2 is a flow diagram illustrating the successive steps of a thermal quenching process according to the invention.
• the invention relates to an electrochromic system (8) deposited on a substrate (1) with a glass function and comprising, in their order of deposit : a first transparent conductive layer (2A) of indium tin oxide (ITO), a working electrode (3) of doped tungsten oxide (WOx), an electrolyte (4) of silica (Si02), a counter- electrode (5) in nickel-tungsten oxide (NiWO), and a second transparent conductive layer (2B) in indium-tin oxide (ITO).
• ITO indium tin oxide
• WOx doped tungsten oxide
• Si02 electrolyte (4) of silica
• NiWO nickel-tungsten oxide
• ITO indium-tin oxide
• Lithium (Li) ions have at this stage already been introduced into said electrochromic system by depositing two distinct layers of Lithium, the first between the working electrode and the electrolyte, the second between the counter-electrode and the second transparent conductive layer, each deposition being followed by a heating step in order to cause diffusion of the lithium ions in the electrochromic stack.
• the layers forming the electrochromic stack are deposited by magnetron. According to an alternative embodiment, at least part of these layers is deposited according to an alternative method, for example via liquid deposition.
• the order of deposition of the electrochromic stack on the substrate is reversed, so that it occurs in the following order of deposition: a first transparent conductive layer (2A ) in indium-tin oxide (ITO), a counter-electrode (5) in nickel-tungsten oxide (NiWO), an electrolyte (4) of silica (Si02), a working electrode (3) of doped tungsten (WOx), and a second conductive layer transparent (2B) also in indium tin oxide (ITO).
• the working electrode is then deposited above the counter electrode.
• the first transparent conductive layer and the working electrode form a cathode sub-assembly (6), while the counter-electrode and the second transparent conductive layer form an anode sub-assembly. (7).
• the assembly is thermally toughened, as illustrated in Figure 2, by heating at high heat to the softening point of the glass, typically at a temperature above 600 ° C., for 5 minutes, then by sudden cooling of the assembly, for example by jets of air and / or inert gas.
• the hardened electrochromic system 8 * obtained then exhibits increased hardness.
• the objective of the tests is to evaluate the thermal quenching resistance performance of different cathode subassemblies, depending on their chemical composition.
• tungsten oxide (WOx) working electrodes respectively doped with 10% atomic mass with Niobium (Nb) (sample no.2), Molybdenum (Mo) (sample no.3) and Vanadium (V ) (sample no.4).
• Nb Niobium
• Mo Molybdenum
• V Vanadium
• the substrate is a 2 mm thick glass. It is first cleaned in order to get rid of any dust which could compromise the proper functioning of the electrochromic stack. The substrate is then placed on a carrier which will cross a deposit line.
• All materials are deposited by magnetron sputtering.
• 400 nm of ITO 2A followed by 380 nm of tungsten oxide (doped or not) 3 are deposited on substrate 2 heated to a temperature of 240 ° C.
• Doped working electrodes are deposited from a doped target. The amount of doping is given by the supplier, and is subsequently verified by micro-analysis on the sample.
• Lithium is then deposited in its metallic form on the cathode sub-assembly 6 thus formed, until the light transmission of the sample at 800 nm, measured using a spectrometer integrated within the line , that is to say between 5% to 50%.
• the sample is quenched in a conventional manner by subjecting it to heating at ⁇ 650 ° C for 5 min before being cooled in ambient air.
• Cyclovoltametry consists in applying a voltage ramp with a defined speed (here 2 mV / s) between two voltage values, and in measuring the current thus created.
• the first series consists in making 10 (ten) cycles between the voltage V0 recorded at time 0, when the sample is connected and the open circuit (voltage at abandonment), and a first voltage V1 greater than V0 then in repeating the operation with increasing values of voltage V1, following an incremental step of 0.1 V.
• the second series consists in carrying out the same operation between V0 and V2 with V2 less than V0 and V2 going towards lower and lower voltages.
• V1 voltage threshold
• V2m voltage threshold
• electrochemistry measurements in three-electrode assembly are carried out.
• the electrodes are bathed in a liquid electrolyte consisting of a 1 mole solution of lithium perchlorate diluted in anhydrous propylene carbonate.
• the cathode sub-assembly studied is electrically connected by means of ultrasound welding before being immersed in the electrolyte.
• This sample cathode sub-assembly then acts as the working electrode of the measuring system with three electrodes, while clean pieces of metallic lithium play the roles of working electrode and counter-electrode.
• the measured voltage is the potential difference between the tested sample and the reference electrode (here metallic Li), while the voltage or current is applied during the experiment between the tested sample and the counter electrode ( here another piece of metallic Li).
• a chronopotentiometry consists in applying a constant current (here 13.4 mA / cm2) and in measuring the voltage at the terminals of the sample and of the counter-electrode. When V1m or V2m is reached, the operation is repeated with a current of opposite sign. Such a cycle is reproduced 20 (twenty) times. From the 20th cycle, by integrating the applied current over the time of a half-cycle, we then obtain the load capacity.
• the contrast is measured on a complete stack.
• the measurement is made in a two-electrode assembly:
• the ITO layer directly in contact with the working electrode constitutes the cathodic sub-assembly while the ITO layer directly in contact with the counter-electrode constitutes the anode subassembly, which plays both the role of reference electrode and counter-electrode of the electrochemical system studied.
• the protocol allowing the determination of the zone of stability of the system can be applied in the same way as described previously.
• a chronoamperometry consists of applying a constant voltage and measuring the current thus created.
• the duration of application of the voltage is chosen such that the current measured at the end of each step changes by less than 0.2 pA / cm2 / min.
• the contrast is then defined as the TLmax / TLmin ratio.
• Sample No. 2 The most important capacity for a quenched sample is that obtained with sample no.2, doped with 10% atomic mass of Niobium (Nb). Sample No. 2 therefore has the most advantageous composition for resisting thermal quenching.

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• Physics & Mathematics (AREA)
• Nonlinear Science (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Crystallography & Structural Chemistry (AREA)
• Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
• Joining Of Glass To Other Materials (AREA)

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• 2019
  • 2019-12-20 FR FR1915268A patent/FR3105459B1/fr active Active
• 2020
  • 2020-12-18 CN CN202080085629.4A patent/CN114746805A/zh active Pending
  • 2020-12-18 US US17/784,460 patent/US20230004058A1/en active Pending
  • 2020-12-18 JP JP2022535173A patent/JP2023507300A/ja active Pending
  • 2020-12-18 EP EP20824948.2A patent/EP4078281A1/de active Pending
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